Fixes for the pure-Lux JVM compiler machinery. [Part 4]

30 files changed, 871 insertions, 603 deletions

diff --git a/stdlib/source/library/lux.lux b/stdlib/source/library/lux.lux
index 4aed1937b..d65fa7bcb 100644
--- a/stdlib/source/library/lux.lux
+++ b/stdlib/source/library/lux.lux
@@ -895,11 +895,8 @@
           {#None}
 
           {#Item [k v] environment'}
-          ({#1
-            {#Some v}
-
-            #0
-            (replacement for environment')}
+          ({[#1] {#Some v}
+            [#0] (replacement for environment')}
            (text#= k for))}
          environment))
 
@@ -999,8 +996,8 @@
           ({... Jackpot!
             {#Parameter id}
             ({id'
-              ({#0 {#Parameter id'}
-                   #1 {#Parameter ("lux i64 -" 2 id')}}
+              ({[#0] {#Parameter id'}
+                [#1] {#Parameter ("lux i64 -" 2 id')}}
                (self_id? id))}
              ("lux i64 -" ("lux i64 -" depth id) 0))
             
@@ -1072,18 +1069,19 @@
            ..#seed _ ..#expected _ ..#location _ ..#extensions _
            ..#scope_type_vars _ ..#eval _]
           (list#mix (function'' [scope verdict]
-                                ({#1 #1
-                                     _ ({[..#name _ ..#inner _ ..#captured _
-                                          ..#locals [..#counter _
-                                                     ..#mappings locals]]
-                                         (list#mix (function'' [local verdict]
-                                                               ({[local _]
-                                                                 ({#1 #1 _ ("lux text =" ..quantification_level local)}
-                                                                  verdict)}
-                                                                local))
-                                                   #0
-                                                   locals)}
-                                        scope)}
+                                ({[#1] #1
+                                  _ ({[..#name _ ..#inner _ ..#captured _
+                                       ..#locals [..#counter _
+                                                  ..#mappings locals]]
+                                      (list#mix (function'' [local verdict]
+                                                            ({[local _]
+                                                              ({[#1] #1
+                                                                _ ("lux text =" ..quantification_level local)}
+                                                               verdict)}
+                                                             local))
+                                                #0
+                                                locals)}
+                                     scope)}
                                  verdict))
                     #0
                     scopes)}
@@ -1094,8 +1092,8 @@
                   {#Item body {#End}}}
            {#Right [lux
                     {#Item ({raw
-                             ({#1 raw
-                                  #0 (..quantified raw)}
+                             ({[#1] raw
+                               [#0] (..quantified raw)}
                               (initialized_quantification? lux))}
                             ({{#End}
                               body
@@ -1126,8 +1124,8 @@
                   {#Item body {#End}}}
            {#Right [lux
                     {#Item ({raw
-                             ({#1 raw
-                                  #0 (..quantified raw)}
+                             ({[#1] raw
+                               [#0] (..quantified raw)}
                               (initialized_quantification? lux))}
                             ({{#End}
                               body
@@ -1301,8 +1299,8 @@
            #0
 
            {#Item x xs'}
-           ({#1  #1
-                 #0 (any? p xs')}
+           ({[#1] #1
+             [#0] (any? p xs')}
             (p x))}
           xs))
 
@@ -1561,40 +1559,38 @@
 
 (def:''' .private (spliced replace? untemplated elems)
          (-> Bit (-> Code ($' Meta Code)) ($' List Code) ($' Meta Code))
-         ({#1
-           ({{#End}
-             (in_meta |#End|)
-             
-             {#Item lastI inits}
-             (do meta_monad
-               [lastO ({[_ {#Form {#Item [[_ {#Symbol ["" "~+"]}] {#Item [spliced {#End}]}]}}]
-                        (in (:List<Code> spliced))
+         ({[#1] ({{#End}
+                  (in_meta |#End|)
+                  
+                  {#Item lastI inits}
+                  (do meta_monad
+                    [lastO ({[_ {#Form {#Item [[_ {#Symbol ["" "~+"]}] {#Item [spliced {#End}]}]}}]
+                             (in (:List<Code> spliced))
 
-                        _
-                        (do meta_monad
-                          [lastO (untemplated lastI)]
-                          (in (:List<Code> (|#Item| lastO |#End|))))}
-                       lastI)]
-               (monad#mix meta_monad
-                          (function' [leftI rightO]
-                                     ({[_ {#Form {#Item [[_ {#Symbol ["" "~+"]}] {#Item [spliced {#End}]}]}}]
-                                       (let' [g!in-module (form$ (list (text$ "lux in-module")
-                                                                       (text$ ..prelude_module)
-                                                                       (symbol$ [..prelude_module "list#composite"])))]
-                                             (in (form$ (list g!in-module (:List<Code> spliced) rightO))))
-
-                                       _
-                                       (do meta_monad
-                                         [leftO (untemplated leftI)]
-                                         (in (|#Item| leftO rightO)))}
-                                      leftI))
-                          lastO
-                          inits))}
-            (list#reversed elems))
-           #0
-           (do meta_monad
-             [=elems (monad#each meta_monad untemplated elems)]
-             (in (untemplated_list =elems)))}
+                             _
+                             (do meta_monad
+                               [lastO (untemplated lastI)]
+                               (in (:List<Code> (|#Item| lastO |#End|))))}
+                            lastI)]
+                    (monad#mix meta_monad
+                               (function' [leftI rightO]
+                                          ({[_ {#Form {#Item [[_ {#Symbol ["" "~+"]}] {#Item [spliced {#End}]}]}}]
+                                            (let' [g!in-module (form$ (list (text$ "lux in-module")
+                                                                            (text$ ..prelude_module)
+                                                                            (symbol$ [..prelude_module "list#composite"])))]
+                                                  (in (form$ (list g!in-module (:List<Code> spliced) rightO))))
+
+                                            _
+                                            (do meta_monad
+                                              [leftO (untemplated leftI)]
+                                              (in (|#Item| leftO rightO)))}
+                                           leftI))
+                               lastO
+                               inits))}
+                 (list#reversed elems))
+           [#0] (do meta_monad
+                  [=elems (monad#each meta_monad untemplated elems)]
+                  (in (untemplated_list =elems)))}
           replace?))
 
 (def:''' .private (untemplated_text value)
@@ -1925,27 +1921,24 @@
 
 (def:''' .private (digit::format digit)
          (-> Nat Text)
-         ({0 "0"
-             1 "1" 2 "2" 3 "3"
-             4 "4" 5 "5" 6 "6"
-             7 "7" 8 "8" 9 "9"
-             _ ("lux io error" "@digit::format Undefined behavior.")}
+         ({[0] "0"
+           [1] "1" [2] "2" [3] "3"
+           [4] "4" [5] "5" [6] "6"
+           [7] "7" [8] "8" [9] "9"
+           _ ("lux io error" "@digit::format Undefined behavior.")}
           digit))
 
 (def:''' .private (nat#encoded value)
          (-> Nat Text)
-         ({0
-           "0"
-
-           _
-           (let' [loop ("lux type check" (-> Nat Text Text)
-                        (function' again [input output]
-                                   (if ("lux i64 =" 0 input)
-                                     output
-                                     (again (n// 10 input)
-                                            (text#composite (|> input (n/% 10) digit::format)
-                                                            output)))))]
-                 (loop value ""))}
+         ({[0] "0"
+           _ (let' [loop ("lux type check" (-> Nat Text Text)
+                          (function' again [input output]
+                                     (if ("lux i64 =" 0 input)
+                                       output
+                                       (again (n// 10 input)
+                                              (text#composite (|> input (n/% 10) digit::format)
+                                                              output)))))]
+                   (loop value ""))}
           value))
 
 (def:''' .private (int#abs value)
diff --git a/stdlib/source/library/lux/control/parser/analysis.lux b/stdlib/source/library/lux/control/parser/analysis.lux
index a59bbfe13..73889de68 100644
--- a/stdlib/source/library/lux/control/parser/analysis.lux
+++ b/stdlib/source/library/lux/control/parser/analysis.lux
@@ -1,6 +1,6 @@
 (.using
   [library
-   [lux {"-" Tuple Variant nat int rev local}
+   [lux {"-" nat int rev local}
     [abstract
      [monad {"+" do}]]
     [control
@@ -30,7 +30,8 @@
        [variable {"+" }]]
       [language
        [lux
-        ["/" analysis {"+" Variant Tuple Environment Analysis}]]]]]]]
+        ["/" analysis {"+" Environment Analysis}
+         ["[1][0]" composite]]]]]]]]
   ["[0]" //])
 
 (def: (remaining_inputs asts)
diff --git a/stdlib/source/library/lux/control/parser/synthesis.lux b/stdlib/source/library/lux/control/parser/synthesis.lux
index 473d6371b..894f7da68 100644
--- a/stdlib/source/library/lux/control/parser/synthesis.lux
+++ b/stdlib/source/library/lux/control/parser/synthesis.lux
@@ -1,32 +1,32 @@
 (.using
-  [library
-   [lux {"-" Tuple Variant function loop i64 local}
-    [abstract
-     [monad {"+" do}]]
-    [control
-     ["[0]" try {"+" Try}]
-     ["[0]" exception {"+" exception:}]]
-    [data
-     ["[0]" bit]
-     ["[0]" text
-      ["%" format {"+" format}]]]
-    [math
-     [number
-      ["n" nat]
-      ["[0]" i64]
-      ["[0]" frac]]]
-    [meta
-     ["[0]" symbol]]
-    [tool
-     [compiler
-      [reference {"+" }
-       [variable {"+" Register}]]
-      [arity {"+" Arity}]
-      [language
-       [lux
-        [analysis {"+" Variant Tuple Environment}]
-        ["/" synthesis {"+" Synthesis Abstraction}]]]]]]]
-  ["[0]" //])
+ [library
+  [lux {"-" function loop i64 local}
+   [abstract
+    [monad {"+" do}]]
+   [control
+    ["[0]" try {"+" Try}]
+    ["[0]" exception {"+" exception:}]]
+   [data
+    ["[0]" bit]
+    ["[0]" text
+     ["%" format {"+" format}]]]
+   [math
+    [number
+     ["n" nat]
+     ["[0]" i64]
+     ["[0]" frac]]]
+   [meta
+    ["[0]" symbol]]
+   [tool
+    [compiler
+     [reference {"+" }
+      [variable {"+" Register}]]
+     [arity {"+" Arity}]
+     [language
+      [lux
+       [analysis {"+" Environment}]
+       ["/" synthesis {"+" Synthesis Abstraction}]]]]]]]
+ ["[0]" //])
 
 (exception: .public (cannot_parse [input (List Synthesis)])
   (exception.report
diff --git a/stdlib/source/library/lux/target/ruby.lux b/stdlib/source/library/lux/target/ruby.lux
index c2d0517c9..df112f23f 100644
--- a/stdlib/source/library/lux/target/ruby.lux
+++ b/stdlib/source/library/lux/target/ruby.lux
@@ -43,18 +43,12 @@
 (abstract: .public (Code brand)
   Text
 
-  (implementation: .public code_equivalence
+  (implementation: .public equivalence
     (All (_ brand) (Equivalence (Code brand)))
 
     (def: (= reference subject)
       (# text.equivalence = (:representation reference) (:representation subject))))
 
-  (implementation: .public code_hash
-    (All (_ brand) (Hash (Code brand)))
-
-    (def: &equivalence ..code_equivalence)
-    (def: hash (|>> :representation (# text.hash hash))))
-
   (def: .public manual
     (-> Text Code)
     (|>> :abstraction))
@@ -223,8 +217,18 @@
             \n+ "end" ..statement_suffix))
 
   (type: .public Block
-    [(List LVar)
-     Statement])
+    (Record
+     [#parameters (List Var)
+      #body Statement]))
+
+  (def: (block it)
+    (-> Block Text)
+    (|> (format (|> (value@ #parameters it)
+                    (list#each (|>> :representation))
+                    (text.interposed ..input_separator)
+                    (text.enclosed' "|"))
+                (..nested (:representation (value@ #body it))))
+        (text.enclosed ["{" "}"])))
 
   (def: .public (apply/* arguments block func)
     (-> (List Expression) (Maybe Block) Expression Computation)
@@ -336,19 +340,18 @@
                                          (..nested (:representation rescue)))))
                     (text.interposed \n+)))))
 
-  (def: .public (catch expectation body!)
-    (-> Expression Statement Statement)
+  (def: .public (catch expectation block)
+    (-> Expression Block Expression)
     (<| :abstraction
-        ..control_structure
-        (format "catch(" (:representation expectation) ") do"
-                (..nested (:representation body!)))))
+        (format "catch(" (:representation expectation) ") "
+                (..block block))))
 
   (def: .public (return value)
     (-> Expression Statement)
     (:abstraction (format "return " (:representation value) ..statement_suffix)))
 
   (def: .public (raise message)
-    (-> Expression Computation)
+    (-> Expression Expression)
     (:abstraction (format "raise " (:representation message))))
 
   (template [<name> <keyword>]
@@ -374,15 +377,9 @@
                     (text.enclosed ["(" ")"]))
                 (..nested (:representation body!)))))
 
-  (def: .public (lambda name args body!)
-    (-> (Maybe LVar) (List Var) Statement Computation)
-    (let [proc (|> (format (|> args
-                               (list#each (|>> :representation))
-                               (text.interposed ..input_separator)
-                               (text.enclosed' "|"))
-                           (..nested (:representation body!)))
-                   (text.enclosed ["{" "}"])
-                   (format "lambda "))]
+  (def: .public (lambda name block)
+    (-> (Maybe LVar) Block Literal)
+    (let [proc (format "lambda " (..block block))]
       (|> (case name
             {.#None}
             proc
@@ -491,12 +488,13 @@
   [2
    [["print"]
     ["alias_method"]]]
-
-  [3
-   [["print"]]]
   )
 
 (def: .public throw/1
   (-> Expression Statement)
   (|>> (..apply/1 (..local "throw"))
        ..statement))
+
+(def: .public (throw/2 tag value)
+  (-> Expression Expression Statement)
+  (..statement (..apply/2 (..local "throw") tag value)))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/analysis.lux b/stdlib/source/library/lux/tool/compiler/language/lux/analysis.lux
index 1b3f70f05..0096a259a 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/analysis.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/analysis.lux
@@ -27,6 +27,7 @@
     ["[0]" location]]]]
  ["[0]" / "_"
   ["[1][0]" primitive {"+" Primitive}]
+  ["[1][0]" composite {"+" Tuple Variant Composite}]
   [//
    [phase
     ["[0]" extension {"+" Extension}]]
@@ -37,41 +38,6 @@
     ["[0]" reference {"+" Reference}
      ["[0]" variable {"+" Register Variable}]]]]])
 
-(type: .public Tag
-  Nat)
-
-(type: .public (Variant a)
-  (Record
-   [#lefts Nat
-    #right? Bit
-    #value a]))
-
-(def: .public (tag lefts right?)
-  (-> Nat Bit Nat)
-  (if right?
-    (++ lefts)
-    lefts))
-
-(def: (lefts tag right?)
-  (-> Nat Bit Nat)
-  (if right?
-    (-- tag)
-    tag))
-
-(def: .public (choice options pick)
-  (-> Nat Nat [Nat Bit])
-  (let [right? (n.= (-- options) pick)]
-    [(..lefts pick right?)
-     right?]))
-
-(type: .public (Tuple a)
-  (List a))
-
-(type: .public (Composite a)
-  (.Variant
-   {#Variant (Variant a)}
-   {#Tuple (Tuple a)}))
-
 (type: .public Pattern
   (Rec Pattern
     (.Variant
@@ -107,42 +73,6 @@
 (type: .public Match
   (Match' Analysis))
 
-(implementation: .public (composite_equivalence (^open "/#[0]"))
-  (All (_ a) (-> (Equivalence a) (Equivalence (Composite a))))
-  
-  (def: (= reference sample)
-    (case [reference sample]
-      [{#Variant [reference_lefts reference_right? reference_value]}
-       {#Variant [sample_lefts sample_right? sample_value]}]
-      (and (n.= reference_lefts sample_lefts)
-           (bit#= reference_right? sample_right?)
-           (/#= reference_value sample_value))
-      
-      [{#Tuple reference} {#Tuple sample}]
-      (# (list.equivalence /#=) = reference sample)
-
-      _
-      false)))
-
-(implementation: .public (composite_hash super)
-  (All (_ a) (-> (Hash a) (Hash (Composite a))))
-
-  (def: &equivalence
-    (..composite_equivalence (# super &equivalence)))
-  
-  (def: (hash value)
-    (case value
-      {#Variant [lefts right? value]}
-      ($_ n.* 2
-          (# n.hash hash lefts)
-          (# bit.hash hash right?)
-          (# super hash value))
-      
-      {#Tuple members}
-      ($_ n.* 3
-          (# (list.hash super) hash members))
-      )))
-
 (implementation: pattern_equivalence
   (Equivalence Pattern)
 
@@ -152,7 +82,7 @@
       (# /primitive.equivalence = reference sample)
       
       [{#Complex reference} {#Complex sample}]
-      (# (composite_equivalence =) = reference sample)
+      (# (/composite.equivalence =) = reference sample)
 
       [{#Bind reference} {#Bind sample}]
       (n.= reference sample)
@@ -176,7 +106,7 @@
       (# /primitive.equivalence = reference sample)
 
       [{#Structure reference} {#Structure sample}]
-      (# (composite_equivalence =) = reference sample)
+      (# (/composite.equivalence =) = reference sample)
 
       [{#Reference reference} {#Reference sample}]
       (# reference.equivalence = reference sample)
@@ -230,10 +160,6 @@
 (type: .public (Application c)
   [c (List c)])
 
-(def: (last? size tag)
-  (-> Nat Tag Bit)
-  (n.= (-- size) tag))
-
 (template: .public (no_op value)
   [(|> 1
        {variable.#Local}
@@ -279,8 +205,8 @@
            <tag>
            content)])]
 
-  [pattern/variant {..#Variant}]
-  [pattern/tuple   {..#Tuple}]
+  [pattern/variant {/composite.#Variant}]
+  [pattern/tuple   {/composite.#Tuple}]
   )
 
 (template [<name> <tag>]
@@ -289,8 +215,8 @@
            {<tag>}
            content)])]
 
-  [variant ..#Variant]
-  [tuple   ..#Tuple]
+  [variant /composite.#Variant]
+  [tuple   /composite.#Tuple]
   )
 
 (template: .public (pattern/unit)
@@ -317,16 +243,8 @@
     {#Primitive it}
     (/primitive.format it)
     
-    {#Structure structure}
-    (case structure
-      {#Variant [lefts right? value]}
-      (format "(" (%.nat lefts) " " (%.bit right?) " " (%analysis value) ")")
-      
-      {#Tuple members}
-      (|> members
-          (list#each %analysis)
-          (text.interposed " ")
-          (text.enclosed ["[" "]"])))
+    {#Structure it}
+    (/composite.format %analysis it)
     
     {#Reference reference}
     (reference.format reference)
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/analysis/composite.lux b/stdlib/source/library/lux/tool/compiler/language/lux/analysis/composite.lux
new file mode 100644
index 000000000..c85f332f9
--- /dev/null
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/analysis/composite.lux
@@ -0,0 +1,98 @@
+(.using
+ [library
+  [lux {"-" Tuple Variant}
+   [abstract
+    [equivalence {"+" Equivalence}]
+    [hash {"+" Hash}]]
+   [data
+    ["[0]" bit ("[1]#[0]" equivalence)]
+    ["[0]" text
+     ["%" format {"+" Format}]]
+    [collection
+     ["[0]" list ("[1]#[0]" functor)]]]
+   [math
+    [number
+     ["n" nat]]]]])
+
+(type: .public (Variant a)
+  (Record
+   [#lefts Nat
+    #right? Bit
+    #value a]))
+
+(type: .public (Tuple a)
+  (List a))
+
+(type: .public (Composite a)
+  (.Variant
+   {#Variant (Variant a)}
+   {#Tuple (Tuple a)}))
+
+(type: .public Tag
+  Nat)
+
+(def: .public (tag right? lefts)
+  (-> Bit Nat Tag)
+  (if right?
+    (++ lefts)
+    lefts))
+
+(def: .public (lefts right? tag)
+  (-> Bit Tag Nat)
+  (if right?
+    (-- tag)
+    tag))
+
+(def: .public (choice multiplicity pick)
+  (-> Nat Tag [Nat Bit])
+  (let [right? (n.= (-- multiplicity) pick)]
+    [(..lefts right? pick)
+     right?]))
+
+(implementation: .public (equivalence (^open "/#[0]"))
+  (All (_ a) (-> (Equivalence a) (Equivalence (Composite a))))
+  
+  (def: (= reference sample)
+    (case [reference sample]
+      [{#Variant [reference_lefts reference_right? reference_value]}
+       {#Variant [sample_lefts sample_right? sample_value]}]
+      (and (n.= reference_lefts sample_lefts)
+           (bit#= reference_right? sample_right?)
+           (/#= reference_value sample_value))
+      
+      [{#Tuple reference} {#Tuple sample}]
+      (# (list.equivalence /#=) = reference sample)
+
+      _
+      false)))
+
+(implementation: .public (hash super)
+  (All (_ a) (-> (Hash a) (Hash (Composite a))))
+
+  (def: &equivalence
+    (..equivalence (# super &equivalence)))
+  
+  (def: (hash value)
+    (case value
+      {#Variant [lefts right? value]}
+      ($_ n.* 2
+          (# n.hash hash lefts)
+          (# bit.hash hash right?)
+          (# super hash value))
+      
+      {#Tuple members}
+      ($_ n.* 3
+          (# (list.hash super) hash members))
+      )))
+
+(def: .public (format %it it)
+  (All (_ a) (-> (Format a) (Format (Composite a))))
+  (case it
+    {#Variant [lefts right? it]}
+    (%.format "{" (%.nat lefts) " " (%.bit right?) " " (%it it) "}")
+    
+    {#Tuple it}
+    (|> it
+        (list#each %it)
+        (text.interposed " ")
+        (text.enclosed ["[" "]"]))))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case.lux
index c2ae6155d..c6e389f6a 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case.lux
@@ -31,7 +31,8 @@
     ["[1][0]" extension]
     [//
      ["/" analysis {"+" Pattern Analysis Operation Phase}
-      ["[1][0]" primitive]]
+      ["[1][0]" primitive]
+      ["[1][0]" composite]]
      [///
       ["[1]" phase]]]]]])
 
@@ -285,7 +286,7 @@
           (let [flat_sum (type.flat_variant inputT')
                 size_sum (list.size flat_sum)
                 num_cases (maybe.else size_sum num_tags)
-                idx (/.tag lefts right?)]
+                idx (/composite.tag right? lefts)]
             (.case (list.item idx flat_sum)
               (^multi {.#Some caseT}
                       (n.< num_cases idx))
@@ -322,7 +323,7 @@
          [idx group variantT] (///extension.lifted (meta.tag tag))
          _ (//type.with_env
              (check.check inputT variantT))
-         .let [[lefts right?] (/.choice (list.size group) idx)]]
+         .let [[lefts right?] (/composite.choice (list.size group) idx)]]
         (analyse_pattern {.#Some (list.size group)} inputT (` {(~ (code.nat lefts)) (~ (code.bit right?)) (~+ values)}) next)))
 
     _
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux
index fd07b53b5..9306b1c20 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/case/coverage.lux
@@ -25,7 +25,8 @@
  ["[0]" //// "_"
   [//
    ["/" analysis {"+" Pattern Operation}
-    ["[1][0]" primitive]]
+    ["[1][0]" primitive]
+    ["[1][0]" composite]]
    [///
     ["[1]" phase ("[1]#[0]" monad)]]]])
 
@@ -138,7 +139,7 @@
 
     ... Tuple patterns can be exhaustive if there is exhaustiveness for all of
     ... their sub-patterns.
-    {/.#Complex {/.#Tuple membersP+}}
+    {/.#Complex {/composite.#Tuple membersP+}}
     (case (list.reversed membersP+)
       (^or {.#End} {.#Item _ {.#End}})
       (/.except ..invalid_tuple_pattern [])
@@ -160,7 +161,7 @@
 
     ... Variant patterns can be shown to be exhaustive if all the possible
     ... cases are handled exhaustively.
-    {/.#Complex {/.#Variant [lefts right? value]}}
+    {/.#Complex {/composite.#Variant [lefts right? value]}}
     (do ////.monad
       [value_coverage (determine value)
        .let [idx (if right?
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/inference.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/inference.lux
index d71ad7c71..6c94f14bd 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/inference.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/inference.lux
@@ -22,7 +22,8 @@
    ["/[1]" // "_"
     ["[1][0]" extension]
     [//
-     ["/" analysis {"+" Tag Analysis Operation Phase}]
+     ["/" analysis {"+" Analysis Operation Phase}
+      [composite {"+" Tag}]]
      [///
       ["[1]" phase ("[1]#[0]" monad)]
       [meta
@@ -248,7 +249,7 @@
 
 ... Turns a variant type into the kind of function type suitable for inference.
 (def: .public (variant tag expected_size inferT)
-  (-> Nat Nat Type (Operation Type))
+  (-> Tag Nat Type (Operation Type))
   (loop [depth 0
          currentT inferT]
     (case currentT
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/structure.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/structure.lux
index 3ba31d089..54eca8afb 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/structure.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/analysis/structure.lux
@@ -32,7 +32,8 @@
    ["/[1]" // "_"
     ["[1][0]" extension]
     [//
-     ["/" analysis {"+" Tag Analysis Operation Phase}]
+     ["/" analysis {"+" Analysis Operation Phase}
+      ["[1][0]" composite {"+" Tag}]]
      [///
       ["[1]" phase]
       [meta
@@ -108,7 +109,7 @@
 
 (def: .public (sum analyse lefts right? archive)
   (-> Phase Nat Bit Phase)
-  (let [tag (/.tag lefts right?)]
+  (let [tag (/composite.tag right? lefts)]
     (function (again valueC)
       (do [! ///.monad]
         [expectedT (///extension.lifted meta.expected_type)
@@ -289,7 +290,7 @@
     [tag (///extension.lifted (meta.normal tag))
      [idx group variantT] (///extension.lifted (meta.tag tag))
      .let [case_size (list.size group)
-           [lefts right?] (/.choice case_size idx)]
+           [lefts right?] (/composite.choice case_size idx)]
      expectedT (///extension.lifted meta.expected_type)]
     (case expectedT
       {.#Var _}
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
index cfee738e6..49a9758bd 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/analysis/jvm.lux
@@ -1,62 +1,63 @@
 (.using
-  [library
-   [lux {"-" Type Module Primitive type char int}
-    ["[0]" ffi {"+" import:}]
-    ["[0]" meta]
-    [abstract
-     ["[0]" monad {"+" do}]]
-    [control
-     pipe
-     ["[0]" maybe]
-     ["[0]" try {"+" Try} ("[1]#[0]" monad)]
-     ["[0]" exception {"+" exception:}]
-     ["<>" parser
-      ["<[0]>" code {"+" Parser}]
-      ["<[0]>" text]]]
-    [data
-     ["[0]" product]
-     ["[0]" text ("[1]#[0]" equivalence)
-      ["%" format {"+" format}]]
-     [collection
-      ["[0]" list ("[1]#[0]" mix monad monoid)]
-      ["[0]" array]
-      ["[0]" dictionary {"+" Dictionary}]]]
-    [math
-     [number
-      ["n" nat]]]
-    [target
-     ["[0]" jvm "_"
-      ["[0]!" reflection]
-      [encoding
-       [name {"+" External}]]
-      ["[1]" type {"+" Type Argument Typed} ("[1]#[0]" equivalence)
-       ["[0]" category {"+" Void Value' Value Return' Return Primitive Object Class Array Var Parameter Method}]
-       ["[0]" box]
-       ["[0]" reflection]
-       ["[0]" descriptor]
-       ["[0]" signature]
-       ["[1]_[0]" parser]
-       ["[1]_[0]" alias {"+" Aliasing}]
-       ["[0]T" lux {"+" Mapping}]]]]
-    ["[0]" type
-     ["[0]" check {"+" Check} ("[1]#[0]" monad)]]]]
-  ["[0]" // "_"
-   ["[1][0]" lux {"+" custom}]
-   ["/[1]" //
-    ["[1][0]" bundle]
+ [library
+  [lux {"-" Type Module Primitive type char int}
+   ["[0]" ffi {"+" import:}]
+   ["[0]" meta]
+   [abstract
+    ["[0]" monad {"+" do}]]
+   [control
+    pipe
+    ["[0]" maybe]
+    ["[0]" try {"+" Try} ("[1]#[0]" monad)]
+    ["[0]" exception {"+" exception:}]
+    ["<>" parser
+     ["<[0]>" code {"+" Parser}]
+     ["<[0]>" text]]]
+   [data
+    ["[0]" product]
+    ["[0]" text ("[1]#[0]" equivalence)
+     ["%" format {"+" format}]]
+    [collection
+     ["[0]" list ("[1]#[0]" mix monad monoid)]
+     ["[0]" array]
+     ["[0]" dictionary {"+" Dictionary}]]]
+   [math
+    [number
+     ["n" nat]]]
+   [target
+    ["[0]" jvm "_"
+     ["[0]!" reflection]
+     [encoding
+      [name {"+" External}]]
+     ["[1]" type {"+" Type Argument Typed} ("[1]#[0]" equivalence)
+      ["[0]" category {"+" Void Value' Value Return' Return Primitive Object Class Array Var Parameter Method}]
+      ["[0]" box]
+      ["[0]" reflection]
+      ["[0]" descriptor]
+      ["[0]" signature]
+      ["[1]_[0]" parser]
+      ["[1]_[0]" alias {"+" Aliasing}]
+      ["[0]T" lux {"+" Mapping}]]]]
+   ["[0]" type
+    ["[0]" check {"+" Check} ("[1]#[0]" monad)]]]]
+ ["[0]" // "_"
+  ["[1][0]" lux {"+" custom}]
+  ["/[1]" //
+   ["[1][0]" bundle]
+   ["/[1]" // "_"
+    [analysis
+     ["[0]A" type]
+     ["[0]A" inference]
+     ["[0]" scope]]
     ["/[1]" // "_"
-     [analysis
-      ["[0]A" type]
-      ["[0]A" inference]
-      ["[0]" scope]]
-     ["/[1]" // "_"
-      ["[1][0]" analysis {"+" Analysis Operation Phase Handler Bundle}]
-      ["[1][0]" synthesis]
-      [///
-       ["[0]" phase ("[1]#[0]" monad)]
-       [meta
-        [archive {"+" Archive}
-         [descriptor {"+" Module}]]]]]]]])
+     ["[1][0]" analysis {"+" Analysis Operation Phase Handler Bundle}
+      ["[1]/[0]" composite]]
+     ["[1][0]" synthesis]
+     [///
+      ["[0]" phase ("[1]#[0]" monad)]
+      [meta
+       [archive {"+" Archive}
+        [descriptor {"+" Module}]]]]]]]])
 
 (import: java/lang/ClassLoader)
 
@@ -1980,9 +1981,10 @@
         {/////analysis.#Case (/////analysis.unit)
                              [[/////analysis.#when
                                {/////analysis.#Complex
-                                {/////analysis.#Tuple (|> arity
-                                                          list.indices
-                                                          (list#each (|>> (n.+ 2) {/////analysis.#Bind})))}}
+                                {/////analysis/composite.#Tuple
+                                 (|> arity
+                                     list.indices
+                                     (list#each (|>> (n.+ 2) {/////analysis.#Bind})))}}
                                
                                /////analysis.#then
                                bodyA]
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux
index 7c70c99ed..dd3816d77 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/jvm/host.lux
@@ -7,20 +7,23 @@
     ["[0]" maybe]
     ["[0]" exception {"+" exception:}]
     ["<>" parser
-     ["<t>" text]
-     ["<s>" synthesis {"+" Parser}]]]
+     ["<[0]>" text]
+     ["<[0]>" synthesis {"+" Parser}]]]
    [data
     ["[0]" product]
     ["[0]" text ("[1]#[0]" equivalence)]
     [collection
-     ["[0]" list ("[1]#[0]" monad monoid)]
+     ["[0]" list ("[1]#[0]" monad mix monoid)]
      ["[0]" dictionary {"+" Dictionary}]
      ["[0]" set {"+" Set}]
      ["[0]" sequence]]
     ["[0]" format "_"
      ["[1]" binary]]]
+   [macro
+    ["[0]" template]]
    [math
     [number
+     ["n" nat]
      ["[0]" i32]]]
    [target
     [jvm
@@ -49,6 +52,7 @@
     ["///" jvm
      ["[1][0]" runtime {"+" Operation Bundle Phase Handler}]
      ["[1][0]" reference]
+     ["[1][0]" value]
      [function
       [field
        [variable
@@ -64,7 +68,7 @@
     [///
      ["[1]" phase]
      ["[1][0]" reference
-      ["[2][0]" variable {"+" Variable}]]
+      ["[2][0]" variable {"+" Variable Register}]]
      [meta
       ["[0]" archive {"+" Archive}
        ["[0]" artifact]
@@ -322,7 +326,7 @@
 (template [<name> <category> <parser>]
   [(def: .public <name>
      (Parser (Type <category>))
-     (<t>.then <parser> <s>.text))]
+     (<text>.then <parser> <synthesis>.text))]
 
   [var Var parser.var]
   [class category.Class parser.class]
@@ -338,7 +342,7 @@
 (def: .public object_array
   (Parser (Type Object))
   (do <>.monad
-    [arrayJT (<t>.then parser.array <s>.text)]
+    [arrayJT (<text>.then parser.array <synthesis>.text)]
     (case (parser.array? arrayJT)
       {.#Some elementJT}
       (case (parser.object? elementJT)
@@ -354,7 +358,7 @@
 (def: (primitive_array_length_handler jvm_primitive)
   (-> (Type Primitive) Handler)
   (..custom
-   [<s>.any
+   [<synthesis>.any
     (function (_ extension_name generate archive arrayS)
       (do //////.monad
         [arrayG (generate archive arrayS)]
@@ -366,7 +370,7 @@
 (def: array::length::object
   Handler
   (..custom
-   [($_ <>.and ..object_array <s>.any)
+   [($_ <>.and ..object_array <synthesis>.any)
     (function (_ extension_name generate archive [elementJT arrayS])
       (do //////.monad
         [arrayG (generate archive arrayS)]
@@ -378,7 +382,7 @@
 (def: (new_primitive_array_handler jvm_primitive)
   (-> Primitive_Array_Type Handler)
   (..custom
-   [<s>.any
+   [<synthesis>.any
     (function (_ extension_name generate archive [lengthS])
       (do //////.monad
         [lengthG (generate archive lengthS)]
@@ -389,7 +393,7 @@
 (def: array::new::object
   Handler
   (..custom
-   [($_ <>.and ..object <s>.any)
+   [($_ <>.and ..object <synthesis>.any)
     (function (_ extension_name generate archive [objectJT lengthS])
       (do //////.monad
         [lengthG (generate archive lengthS)]
@@ -400,7 +404,7 @@
 (def: (read_primitive_array_handler jvm_primitive loadG)
   (-> (Type Primitive) (Bytecode Any) Handler)
   (..custom
-   [($_ <>.and <s>.any <s>.any)
+   [($_ <>.and <synthesis>.any <synthesis>.any)
     (function (_ extension_name generate archive [idxS arrayS])
       (do //////.monad
         [arrayG (generate archive arrayS)
@@ -414,7 +418,7 @@
 (def: array::read::object
   Handler
   (..custom
-   [($_ <>.and ..object_array <s>.any <s>.any)
+   [($_ <>.and ..object_array <synthesis>.any <synthesis>.any)
     (function (_ extension_name generate archive [elementJT idxS arrayS])
       (do //////.monad
         [arrayG (generate archive arrayS)
@@ -428,7 +432,7 @@
 (def: (write_primitive_array_handler jvm_primitive storeG)
   (-> (Type Primitive) (Bytecode Any) Handler)
   (..custom
-   [($_ <>.and <s>.any <s>.any <s>.any)
+   [($_ <>.and <synthesis>.any <synthesis>.any <synthesis>.any)
     (function (_ extension_name generate archive [idxS valueS arrayS])
       (do //////.monad
         [arrayG (generate archive arrayS)
@@ -445,7 +449,7 @@
 (def: array::write::object
   Handler
   (..custom
-   [($_ <>.and ..object_array <s>.any <s>.any <s>.any)
+   [($_ <>.and ..object_array <synthesis>.any <synthesis>.any <synthesis>.any)
     (function (_ extension_name generate archive [elementJT idxS valueS arrayS])
       (do //////.monad
         [arrayG (generate archive arrayS)
@@ -549,7 +553,7 @@
 (def: object::class
   Handler
   (..custom
-   [<s>.text
+   [<synthesis>.text
     (function (_ extension_name generate archive [class])
       (do //////.monad
         []
@@ -560,7 +564,7 @@
 (def: object::instance?
   Handler
   (..custom
-   [($_ <>.and <s>.text <s>.any)
+   [($_ <>.and <synthesis>.text <synthesis>.any)
     (function (_ extension_name generate archive [class objectS])
       (do //////.monad
         [objectG (generate archive objectS)]
@@ -577,7 +581,7 @@
 (def: object::cast
   Handler
   (..custom
-   [($_ <>.and <s>.text <s>.text <s>.any)
+   [($_ <>.and <synthesis>.text <synthesis>.text <synthesis>.any)
     (function (_ extension_name generate archive [from to valueS])
       (do //////.monad
         [valueG (generate archive valueS)]
@@ -640,7 +644,7 @@
 (def: get::static
   Handler
   (..custom
-   [($_ <>.and <s>.text <s>.text <s>.text)
+   [($_ <>.and <synthesis>.text <synthesis>.text <synthesis>.text)
     (function (_ extension_name generate archive [class field unboxed])
       (do //////.monad
         [.let [$class (type.class class (list))]]
@@ -656,7 +660,7 @@
 (def: put::static
   Handler
   (..custom
-   [($_ <>.and <s>.text <s>.text <s>.text <s>.any)
+   [($_ <>.and <synthesis>.text <synthesis>.text <synthesis>.text <synthesis>.any)
     (function (_ extension_name generate archive [class field unboxed valueS])
       (do //////.monad
         [valueG (generate archive valueS)
@@ -678,7 +682,7 @@
 (def: get::virtual
   Handler
   (..custom
-   [($_ <>.and <s>.text <s>.text <s>.text <s>.any)
+   [($_ <>.and <synthesis>.text <synthesis>.text <synthesis>.text <synthesis>.any)
     (function (_ extension_name generate archive [class field unboxed objectS])
       (do //////.monad
         [objectG (generate archive objectS)
@@ -697,7 +701,7 @@
 (def: put::virtual
   Handler
   (..custom
-   [($_ <>.and <s>.text <s>.text <s>.text <s>.any <s>.any)
+   [($_ <>.and <synthesis>.text <synthesis>.text <synthesis>.text <synthesis>.any <synthesis>.any)
     (function (_ extension_name generate archive [class field unboxed valueS objectS])
       (do //////.monad
         [valueG (generate archive valueS)
@@ -724,7 +728,7 @@
 
 (def: input
   (Parser Input)
-  (<s>.tuple (<>.and ..value <s>.any)))
+  (<synthesis>.tuple (<>.and ..value <synthesis>.any)))
 
 (def: (generate_input generate archive [valueT valueS])
   (-> Phase Archive Input (Operation (Typed (Bytecode Any))))
@@ -751,7 +755,7 @@
 (def: invoke::static
   Handler
   (..custom
-   [($_ <>.and ..class <s>.text ..return (<>.some ..input))
+   [($_ <>.and ..class <synthesis>.text ..return (<>.some ..input))
     (function (_ extension_name generate archive [class method outputT inputsTS])
       (do [! //////.monad]
         [inputsTG (monad.each ! (generate_input generate archive) inputsTS)]
@@ -764,7 +768,7 @@
   [(def: <name>
      Handler
      (..custom
-      [($_ <>.and ..class <s>.text ..return <s>.any (<>.some ..input))
+      [($_ <>.and ..class <synthesis>.text ..return <synthesis>.any (<>.some ..input))
        (function (_ extension_name generate archive [class method outputT objectS inputsTS])
          (do [! //////.monad]
            [objectG (generate archive objectS)
@@ -817,36 +821,72 @@
 
 (def: annotation_parameter
   (Parser (/.Annotation_Parameter Synthesis))
-  (<s>.tuple (<>.and <s>.text <s>.any)))
+  (<synthesis>.tuple (<>.and <synthesis>.text <synthesis>.any)))
 
 (def: annotation
   (Parser (/.Annotation Synthesis))
-  (<s>.tuple (<>.and <s>.text (<>.some ..annotation_parameter))))
+  (<synthesis>.tuple (<>.and <synthesis>.text (<>.some ..annotation_parameter))))
 
 (def: argument
   (Parser Argument)
-  (<s>.tuple (<>.and <s>.text ..value)))
+  (<synthesis>.tuple (<>.and <synthesis>.text ..value)))
+
+(def: .public (hidden_method_body arity body)
+  (-> Nat Synthesis Synthesis)
+  (case [arity body]
+    (^or [0 _]
+         [1 _])
+    body
+    
+    (^or [2 {//////synthesis.#Control {//////synthesis.#Branch {//////synthesis.#Let _ 2 hidden}}}]
+         [2 {//////synthesis.#Control {//////synthesis.#Branch {//////synthesis.#Exec _ hidden}}}])
+    hidden
+    
+    [_ {//////synthesis.#Control {//////synthesis.#Branch {//////synthesis.#Case _ path}}}]
+    (loop [path (: Path path)]
+      (case path
+        (^or {//////synthesis.#Pop}
+             {//////synthesis.#Access _}
+             {//////synthesis.#Bind _}
+             {//////synthesis.#Bit_Fork _}
+             {//////synthesis.#I64_Fork _}
+             {//////synthesis.#F64_Fork _}
+             {//////synthesis.#Text_Fork _}
+             {//////synthesis.#Alt _})
+        body
+        
+        {//////synthesis.#Seq _ next}
+        (again next)
+        
+        {//////synthesis.#Then hidden}
+        hidden))
+
+    _
+    body))
 
 (def: overriden_method_definition
   (Parser [(Environment Synthesis) (/.Overriden_Method Synthesis)])
-  (<s>.tuple (do <>.monad
-               [_ (<s>.text! /.overriden_tag)
-                ownerT ..class
-                name <s>.text
-                strict_fp? <s>.bit
-                annotations (<s>.tuple (<>.some ..annotation))
-                vars (<s>.tuple (<>.some ..var))
-                self_name <s>.text
-                arguments (<s>.tuple (<>.some ..argument))
-                returnT ..return
-                exceptionsT (<s>.tuple (<>.some ..class))
-                [environment body] (<s>.function 1
-                                     (<s>.tuple <s>.any))]
-               (in [environment
-                    [ownerT name
-                     strict_fp? annotations vars
-                     self_name arguments returnT exceptionsT
-                     body]]))))
+  (<synthesis>.tuple (do <>.monad
+                       [_ (<synthesis>.text! /.overriden_tag)
+                        ownerT ..class
+                        name <synthesis>.text
+                        strict_fp? <synthesis>.bit
+                        annotations (<synthesis>.tuple (<>.some ..annotation))
+                        vars (<synthesis>.tuple (<>.some ..var))
+                        self_name <synthesis>.text
+                        arguments (<synthesis>.tuple (<>.some ..argument))
+                        returnT ..return
+                        exceptionsT (<synthesis>.tuple (<>.some ..class))
+                        [environment _ _ body] (<| (<synthesis>.function 1)
+                                                   (<synthesis>.loop (<>.exactly 0 <synthesis>.any))
+                                                   <synthesis>.tuple
+                                                   (<>.after <synthesis>.any)
+                                                   <synthesis>.any)]
+                       (in [environment
+                            [ownerT name
+                             strict_fp? annotations vars
+                             self_name arguments returnT exceptionsT
+                             (..hidden_method_body (list.size arguments) body)]]))))
 
 (def: (normalize_path normalize)
   (-> (-> Synthesis Synthesis)
@@ -872,8 +912,11 @@
       _
       (undefined))))
 
+(type: Mapping
+  (Dictionary Synthesis Variable))
+
 (def: (normalize_method_body mapping)
-  (-> (Dictionary Variable Variable) Synthesis Synthesis)
+  (-> Mapping Synthesis Synthesis)
   (function (again body)
     (case body
       (^template [<tag>]
@@ -890,7 +933,7 @@
 
       (^ (//////synthesis.variable var))
       (|> mapping
-          (dictionary.value var)
+          (dictionary.value body)
           (maybe.else var)
           //////synthesis.variable)
 
@@ -916,16 +959,16 @@
       (//////synthesis.loop/again (list#each again updatesS+))
 
       (^ (//////synthesis.function/abstraction [environment arity bodyS]))
-      (//////synthesis.function/abstraction [(list#each (function (_ local)
-                                                          (case local
-                                                            (^ (//////synthesis.variable local))
+      (//////synthesis.function/abstraction [(list#each (function (_ captured)
+                                                          (case captured
+                                                            (^ (//////synthesis.variable var))
                                                             (|> mapping
-                                                                (dictionary.value local)
-                                                                (maybe.else local)
+                                                                (dictionary.value captured)
+                                                                (maybe.else var)
                                                                 //////synthesis.variable)
 
                                                             _
-                                                            local))
+                                                            captured))
                                                         environment)
                                              arity
                                              bodyS])
@@ -984,26 +1027,34 @@
     {.#Left returnT}
     (case (type.primitive? returnT)
       {.#Left returnT}
-      ($_ _.composite
-          (_.checkcast returnT)
-          _.areturn)
+      (case (type.class? returnT)
+        {.#Some class_name}
+        ($_ _.composite
+            (_.checkcast returnT)
+            _.areturn)
+
+        {.#None}
+        _.areturn)
       
       {.#Right returnT}
-      (cond (or (# type.equivalence = type.boolean returnT)
-                (# type.equivalence = type.byte returnT)
-                (# type.equivalence = type.short returnT)
-                (# type.equivalence = type.int returnT)
-                (# type.equivalence = type.char returnT))
-            _.ireturn
-
-            (# type.equivalence = type.long returnT)
-            _.lreturn
-
-            (# type.equivalence = type.float returnT)
-            _.freturn
-
-            ... (# type.equivalence = type.double returnT)
-            _.dreturn))))
+      (template.let [(unwrap_primitive <return> <type>)
+                     [($_ _.composite
+                          (///value.unwrap <type>)
+                          <return>)]]
+        (`` (cond (~~ (template [<return> <type>]
+                        [(# type.equivalence = <type> returnT)
+                         (unwrap_primitive <return> <type>)]
+
+                        [_.ireturn type.boolean]
+                        [_.ireturn type.byte]
+                        [_.ireturn type.short]
+                        [_.ireturn type.int]
+                        [_.ireturn type.char]
+                        [_.freturn type.float]
+                        [_.lreturn type.long]))
+
+                  ... (# type.equivalence = type.double returnT)
+                  (unwrap_primitive _.dreturn type.double)))))))
 
 (def: (method_dependencies archive method)
   (-> Archive (/.Overriden_Method Synthesis) (Operation (Set artifact.Dependency)))
@@ -1027,15 +1078,124 @@
                             all_closure_dependencies
                             all_method_dependencies)))))
 
+(def: (prepare_argument lux_register argumentT jvm_register)
+  (-> Register (Type Value) Register [Register (Bytecode Any)])
+  (case (type.primitive? argumentT)
+    {.#Left argumentT}
+    [(n.+ 1 jvm_register)
+     (if (n.= lux_register jvm_register)
+       (_#in [])
+       ($_ _.composite
+           (_.aload jvm_register)
+           (_.astore lux_register)))]
+    
+    {.#Right argumentT}
+    (template.let [(wrap_primitive <shift> <load> <type>)
+                   [[(n.+ <shift> jvm_register)
+                     ($_ _.composite
+                         (<load> jvm_register)
+                         (///value.wrap <type>)
+                         (_.astore lux_register))]]]
+      (`` (cond (~~ (template [<shift> <load> <type>]
+                      [(# type.equivalence = <type> argumentT)
+                       (wrap_primitive <shift> <load> <type>)]
+
+                      [1 _.iload type.boolean]
+                      [1 _.iload type.byte]
+                      [1 _.iload type.short]
+                      [1 _.iload type.int]
+                      [1 _.iload type.char]
+                      [1 _.fload type.float]
+                      [2 _.lload type.long]))
+
+                ... (# type.equivalence = type.double argumentT)
+                (wrap_primitive 2 _.dload type.double))))))
+
+(def: .public (prepare_arguments offset types)
+  (-> Nat (List (Type Value)) (Bytecode Any))
+  (|> types
+      list.enumeration
+      (list#mix (function (_ [lux_register type] [jvm_register before])
+                  (let [[jvm_register' after] (prepare_argument (n.+ offset lux_register) type jvm_register)]
+                    [jvm_register'
+                     ($_ _.composite
+                         before
+                         after)]))
+                (: [Register (Bytecode Any)]
+                   [offset
+                    (_#in [])]))
+      product.right))
+
+(def: (normalized_method global_mapping [environment method])
+  (-> Mapping [(Environment Synthesis) (/.Overriden_Method Synthesis)]
+      (/.Overriden_Method Synthesis))
+  (let [[ownerT name strict_fp? annotations vars self_name arguments returnT exceptionsT body] method
+        local_mapping (|> environment
+                          list.enumeration
+                          (list#each (function (_ [foreign_id capture])
+                                       [(//////synthesis.variable/foreign foreign_id)
+                                        (|> global_mapping
+                                            (dictionary.value capture)
+                                            maybe.trusted)]))
+                          (dictionary.of_list //////synthesis.hash))]
+    [ownerT name
+     strict_fp? annotations vars
+     self_name arguments returnT exceptionsT
+     (normalize_method_body local_mapping body)]))
+
+(def: (total_environment overriden_methods)
+  (-> (List [(Environment Synthesis) (/.Overriden_Method Synthesis)])
+      (List Synthesis))
+  (|> overriden_methods
+      ... Get all the environments.
+      (list#each product.left)
+      ... Combine them.
+      list#conjoint
+      ... Remove duplicates.
+      (set.of_list //////synthesis.hash)
+      set.list))
+
+(def: (global_mapping total_environment)
+  (-> (List Synthesis) Mapping)
+  (|> total_environment
+      ... Give them names as "foreign" variables.
+      list.enumeration
+      (list#each (function (_ [id capture])
+                   [capture {//////variable.#Foreign id}]))
+      (dictionary.of_list //////synthesis.hash)))
+
+(def: (method_definition phase archive artifact_id method)
+  (-> Phase Archive artifact.ID (/.Overriden_Method Synthesis) (Operation (Resource Method)))
+  (let [[ownerT name strict_fp? annotations vars self_name arguments returnT exceptionsT bodyS] method]
+    (do //////.monad
+      [bodyG (//////generation.with_context artifact_id
+               (phase archive bodyS))
+       .let [argumentsT (list#each product.right arguments)
+             methodT (type.method [vars argumentsT returnT exceptionsT])]]
+      (in (method.method ($_ modifier#composite
+                             method.public
+                             method.final
+                             (if strict_fp?
+                               method.strict
+                               modifier#identity))
+                         name
+                         methodT
+                         (list)
+                         {.#Some ($_ _.composite
+                                     (prepare_arguments 1 argumentsT)
+                                     bodyG
+                                     (returnG returnT))})))))
+
 (def: class::anonymous
   Handler
   (..custom
    [($_ <>.and
         ..class
-        (<s>.tuple (<>.some ..class))
-        (<s>.tuple (<>.some ..input))
-        (<s>.tuple (<>.some ..overriden_method_definition)))
-    (function (_ extension_name generate archive [super_class super_interfaces
+        (<synthesis>.tuple (<>.some ..class))
+        (<synthesis>.tuple (<>.some ..input))
+        (<synthesis>.tuple (<>.some ..overriden_method_definition)))
+    (function (_ extension_name generate archive [super_class
+                                                  super_interfaces
                                                   inputsTS
                                                   overriden_methods])
       (do [! //////.monad]
@@ -1044,62 +1204,12 @@
          .let [[module_id artifact_id] context
                anonymous_class_name (///runtime.class_name context)
                class (type.class anonymous_class_name (list))
-               total_environment (|> overriden_methods
-                                     ... Get all the environments.
-                                     (list#each product.left)
-                                     ... Combine them.
-                                     list#conjoint
-                                     ... Remove duplicates.
-                                     (set.of_list //////synthesis.hash)
-                                     set.list)
-               global_mapping (|> total_environment
-                                  ... Give them names as "foreign" variables.
-                                  list.enumeration
-                                  (list#each (function (_ [id capture])
-                                               [capture {//////variable.#Foreign id}]))
-                                  (dictionary.of_list //////synthesis.hash))
-               normalized_methods (list#each (function (_ [environment
-                                                           [ownerT name
-                                                            strict_fp? annotations vars
-                                                            self_name arguments returnT exceptionsT
-                                                            body]])
-                                               (let [local_mapping (|> environment
-                                                                       list.enumeration
-                                                                       (list#each (function (_ [foreign_id capture])
-                                                                                    [{//////variable.#Foreign foreign_id}
-                                                                                     (|> global_mapping
-                                                                                         (dictionary.value capture)
-                                                                                         maybe.trusted)]))
-                                                                       (dictionary.of_list //////variable.hash))]
-                                                 [ownerT name
-                                                  strict_fp? annotations vars
-                                                  self_name arguments returnT exceptionsT
-                                                  (normalize_method_body local_mapping body)]))
-                                             overriden_methods)]
+               total_environment (..total_environment overriden_methods)
+               global_mapping (..global_mapping total_environment)]
          inputsTI (monad.each ! (generate_input generate archive) inputsTS)
-         method_definitions (monad.each ! (function (_ [ownerT name
-                                                        strict_fp? annotations vars
-                                                        self_name arguments returnT exceptionsT
-                                                        bodyS])
-                                            (do !
-                                              [bodyG (//////generation.with_context artifact_id
-                                                       (generate archive bodyS))]
-                                              (in (method.method ($_ modifier#composite
-                                                                     method.public
-                                                                     method.final
-                                                                     (if strict_fp?
-                                                                       method.strict
-                                                                       modifier#identity))
-                                                                 name
-                                                                 (type.method [(list)
-                                                                               (list#each product.right arguments)
-                                                                               returnT
-                                                                               exceptionsT])
-                                                                 (list)
-                                                                 {.#Some ($_ _.composite
-                                                                             bodyG
-                                                                             (returnG returnT))}))))
-                                        normalized_methods)
+         methods! (|> overriden_methods
+                      (list#each (normalized_method global_mapping))
+                      (monad.each ! (method_definition generate archive artifact_id)))
          bytecode (<| (# ! each (format.result class.writer))
                       //////.lifted
                       (class.class version.v6_0 ($_ modifier#composite class.public class.final)
@@ -1108,10 +1218,11 @@
                                    (list#each (|>> ..reflection name.internal) super_interfaces)
                                    (foreign.variables total_environment)
                                    (list& (..with_anonymous_init class total_environment super_class inputsTI)
-                                          method_definitions)
+                                          methods!)
                                    (sequence.sequence)))
-         _ (//////generation.execute! [anonymous_class_name bytecode])
-         _ (//////generation.save! artifact_id {.#None} [anonymous_class_name bytecode])]
+         .let [artifact [anonymous_class_name bytecode]]
+         _ (//////generation.execute! artifact)
+         _ (//////generation.save! artifact_id {.#None} artifact)]
         (anonymous_instance generate archive class total_environment)))]))
 
 (def: bundle::class
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/ruby/common.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/ruby/common.lux
index a65557eeb..2328c2f2a 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/ruby/common.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/extension/generation/ruby/common.lux
@@ -88,7 +88,8 @@
     (^template [<tag> <generator>]
       [(^ (<tag> value))
        (<generator> statement expression archive value)])
-    ([synthesis.branch/let //case.let!]
+    ([synthesis.branch/exec //case.exec!]
+     [synthesis.branch/let //case.let!]
      [synthesis.branch/if //case.if!]
      [synthesis.loop/scope //loop.scope!]
      [synthesis.loop/again //loop.again!])
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux
index 5a1ec9ea6..7827fee86 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/jvm/structure.lux
@@ -21,8 +21,9 @@
   ["[1][0]" runtime {"+" Operation Phase Generator}]
   ["[1][0]" primitive]
   ["///[1]" //// "_"
-   [analysis {"+" Variant Tuple}]
    ["[1][0]" synthesis {"+" Synthesis}]
+   [analysis
+    [composite {"+" Variant Tuple}]]
    [///
     ["[0]" phase]]]])
 
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby.lux
index 02170332c..ca563e3e1 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby.lux
@@ -49,6 +49,7 @@
     ([////synthesis.variant /structure.variant]
      [////synthesis.tuple /structure.tuple]
      
+     [////synthesis.branch/exec /case.exec]
      [////synthesis.branch/let /case.let]
      [////synthesis.branch/if /case.if]
      [////synthesis.branch/get /case.get]
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/case.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/case.lux
index 766b4fa43..400e47cfb 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/case.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/case.lux
@@ -1,6 +1,6 @@
 (.using
  [library
-  [lux {"-" case let if symbol}
+  [lux {"-" case exec let if symbol}
    [abstract
     ["[0]" monad {"+" do}]]
    [control
@@ -48,6 +48,24 @@
   (-> Register LVar)
   (|>> (///reference.foreign //reference.system) :expected))
 
+(def: .public (exec expression archive [this that])
+  (Generator [Synthesis Synthesis])
+  (do ///////phase.monad
+    [this (expression archive this)
+     that (expression archive that)]
+    (in (|> (_.array (list this that))
+            (_.item (_.int +1))))))
+
+(def: .public (exec! statement expression archive [this that])
+  (Generator! [Synthesis Synthesis])
+  (do ///////phase.monad
+    [this (expression archive this)
+     that (statement expression archive that)]
+    (in ($_ _.then
+            (_.statement this)
+            that
+            ))))
+
 (def: .public (let expression archive [valueS register bodyS])
   (Generator [Synthesis Register Synthesis])
   (do ///////phase.monad
@@ -56,7 +74,7 @@
     ... TODO: Find some way to do 'let' without paying the price of the closure.
     (in (|> bodyO
             _.return
-            (_.lambda {.#None} (list (..register register)))
+            [(list (..register register))] (_.lambda {.#None})
             (_.apply_lambda/* (list valueO))))))
 
 (def: .public (let! statement expression archive [valueS register bodyS])
@@ -217,8 +235,10 @@
                                                 ..peek)])
                                      (again then)))
                               {.#Item item})]
-         (in {.#Some (_.cond clauses
-                             ..fail!)}))])
+         (in {.#Some (list#mix (function (_ [when then] else)
+                                 (_.if when then else))
+                               ..fail!
+                               clauses)}))])
     ([/////synthesis.#I64_Fork (<| //primitive.i64 .int)]
      [/////synthesis.#F64_Fork (<| //primitive.f64)]
      [/////synthesis.#Text_Fork (<| //primitive.text)])
@@ -272,8 +292,10 @@
                                                       ..peek)])
                                            (again then)))
                                     {.#Item item})]
-               (in (_.cond clauses
-                           ..fail!)))])
+               (in (list#mix (function (_ [when then] else)
+                               (_.if when then else))
+                             ..fail!
+                             clauses)))])
           ([/////synthesis.#I64_Fork (<| //primitive.i64 .int)]
            [/////synthesis.#F64_Fork (<| //primitive.f64)]
            [/////synthesis.#Text_Fork (<| //primitive.text)])
@@ -356,5 +378,5 @@
   (|> case
       (case! true statement expression archive)
       (# ///////phase.monad each
-         (|>> (_.lambda {.#None} (list))
+         (|>> [(list)] (_.lambda {.#None})
               (_.apply_lambda/* (list))))))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/function.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/function.lux
index ccad8ba2a..16dab0814 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/function.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/function.lux
@@ -1,6 +1,6 @@
 (.using
  [library
-  [lux {"-" Variant Tuple function}
+  [lux {"-" function}
    [abstract
     ["[0]" monad {"+" do}]]
    [data
@@ -19,7 +19,7 @@
   ["/[1]" // "_"
    ["[1][0]" reference]
    ["//[1]" /// "_"
-    [analysis {"+" Variant Tuple Environment Abstraction Application Analysis}]
+    [analysis {"+" Environment Abstraction Application Analysis}]
     [synthesis {"+" Synthesis}]
     ["[1][0]" generation {"+" Context}]
     ["//[1]" /// "_"
@@ -52,12 +52,12 @@
 
       _
       [(_.set (list @self) (_.lambda {.#None}
-                                     (|> (list.enumeration inits)
-                                         (list#each (|>> product.left ..capture)))
-                                     (let [@self (_.local self)]
-                                       ($_ _.then
-                                           (_.set (list @self) function_definition)
-                                           (_.return @self)))))
+                                     [(|> (list.enumeration inits)
+                                          (list#each (|>> product.left ..capture)))
+                                      (let [@self (_.local self)]
+                                        ($_ _.then
+                                            (_.set (list @self) function_definition)
+                                            (_.return @self)))]))
        (_.apply_lambda/* inits @self)])))
 
 (def: input
@@ -91,29 +91,31 @@
                                  initialize_self!
                                  (list.indices arity))
            [declaration instatiation] (with_closure closureO+ function_name
-                                        (_.lambda {.#None} (list (_.variadic @curried))
-                                                  ($_ _.then
-                                                      (_.set (list @num_args) (_.the "length" @curried))
-                                                      (_.cond (list [(|> @num_args (_.= arityO))
-                                                                     (<| (_.then initialize!)
-                                                                         //loop.with_scope
-                                                                         body!)]
-                                                                    [(|> @num_args (_.> arityO))
-                                                                     (let [slice (.function (_ from to)
-                                                                                   (_.array_range from to @curried))
-                                                                           arity_args (_.splat (slice (_.int +0) limitO))
-                                                                           output_func_args (_.splat (slice arityO @num_args))]
-                                                                       (_.return (|> @self
-                                                                                     (_.apply_lambda/* (list arity_args))
-                                                                                     (_.apply_lambda/* (list output_func_args)))))])
-                                                              ... (|> @num_args (_.< arityO))
-                                                              (let [@missing (_.local "missing")]
-                                                                (_.return (_.lambda {.#None} (list (_.variadic @missing))
-                                                                                    (_.return (|> @self
-                                                                                                  (_.apply_lambda/* (list (_.splat (|> (_.array (list))
-                                                                                                                                       (_.do "concat" (list @curried) {.#None})
-                                                                                                                                       (_.do "concat" (list @missing) {.#None})))))))))))
-                                                      )))]
+                                        (_.lambda {.#None}
+                                                  [(list (_.variadic @curried))
+                                                   ($_ _.then
+                                                       (_.set (list @num_args) (_.the "length" @curried))
+                                                       (<| (_.if (|> @num_args (_.= arityO))
+                                                             (<| (_.then initialize!)
+                                                                 //loop.with_scope
+                                                                 body!))
+                                                           (_.if (|> @num_args (_.> arityO))
+                                                             (let [slice (.function (_ from to)
+                                                                           (_.array_range from to @curried))
+                                                                   arity_args (_.splat (slice (_.int +0) limitO))
+                                                                   output_func_args (_.splat (slice arityO @num_args))]
+                                                               (_.return (|> @self
+                                                                             (_.apply_lambda/* (list arity_args))
+                                                                             (_.apply_lambda/* (list output_func_args))))))
+                                                           ... (|> @num_args (_.< arityO))
+                                                           (let [@missing (_.local "missing")]
+                                                             (_.return (_.lambda {.#None}
+                                                                                 [(list (_.variadic @missing))
+                                                                                  (_.return (|> @self
+                                                                                                (_.apply_lambda/* (list (_.splat (|> (_.array (list))
+                                                                                                                                     (_.do "concat" (list @curried) {.#None})
+                                                                                                                                     (_.do "concat" (list @missing) {.#None})))))))]))))
+                                                       )]))]
      _ (/////generation.execute! declaration)
      _ (/////generation.save! function_artifact {.#None} declaration)]
     (in instatiation)))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/loop.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/loop.lux
index b4dbf8248..9ccd0151e 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/loop.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/loop.lux
@@ -77,7 +77,7 @@
     (do [! ///////phase.monad]
       [body! (scope! statement expression archive [start initsS+ bodyS])]
       (in (|> body!
-              (_.lambda {.#None} (list))
+              [(list)] (_.lambda {.#None})
               (_.apply_lambda/* (list)))))))
 
 (def: .public (again! statement expression archive argsS+)
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/runtime.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/runtime.lux
index af0f3338c..d82d5e7ba 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/runtime.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/runtime.lux
@@ -171,12 +171,12 @@
           ($_ _.then
               (_.set (list last_index_right) (..last_index tuple))
               (_.set (list right_index) (_.+ (_.int +1) lefts))
-              (_.cond (list [(_.= last_index_right right_index)
-                             (_.return (_.item right_index tuple))]
-                            [(_.> last_index_right right_index)
-                             ... Needs recursion.
-                             <recur>])
-                      (_.return (_.array_range right_index (..tuple_size tuple) tuple)))
+              (<| (_.if (_.= last_index_right right_index)
+                    (_.return (_.item right_index tuple)))
+                  (_.if (_.> last_index_right right_index)
+                    ... Needs recursion.
+                    <recur>)
+                  (_.return (_.array_range right_index (..tuple_size tuple) tuple)))
               )))))
 
 (def: .public variant_tag_field "_lux_tag")
@@ -219,24 +219,21 @@
                                                      (_.- (_.int +1))))
                    (_.set (list sum) actual##value))]
     (<| (_.while (_.bool true))
-        (_.cond (list [(_.= expected##lefts actual##lefts)
-                       (_.if (_.= expected##right? actual##right?)
-                         (_.return actual##value)
-                         mismatch!)]
-
-                      [(_.< expected##lefts actual##lefts)
-                       (_.if (_.= ..unit actual##right?)
-                         recur!
-                         mismatch!)]
-
-                      [(_.= ..unit expected##right?)
-                       (_.return (sum//make (|> actual##lefts
-                                                (_.- expected##lefts)
-                                                (_.- (_.int +1)))
-                                            actual##right?
-                                            actual##value))])
-
-                mismatch!))))
+        (_.if (_.= expected##lefts actual##lefts)
+          (_.if (_.= expected##right? actual##right?)
+            (_.return actual##value)
+            mismatch!))
+        (_.if (_.< expected##lefts actual##lefts)
+          (_.if (_.= ..unit actual##right?)
+            recur!
+            mismatch!))
+        (_.if (_.= ..unit expected##right?)
+          (_.return (sum//make (|> actual##lefts
+                                   (_.- expected##lefts)
+                                   (_.- (_.int +1)))
+                               actual##right?
+                               actual##value)))
+        mismatch!)))
 
 (def: runtime//adt
   Statement
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/structure.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/structure.lux
index 72c620827..27361d558 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/structure.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/generation/ruby/structure.lux
@@ -9,7 +9,8 @@
   ["[1][0]" runtime {"+" Operation Phase Generator}]
   ["[1][0]" primitive]
   ["///[1]" //// "_"
-   [analysis {"+" Variant Tuple}]
+   [analysis
+    [composite {"+" Variant Tuple}]]
    ["[1][0]" synthesis {"+" Synthesis}]
    ["//[1]" /// "_"
     ["[1][0]" phase ("[1]#[0]" monad)]]]])
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis.lux
index 68f3c22d4..e8aec1a83 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis.lux
@@ -19,7 +19,8 @@
    ["/[1]" // "_"
     ["/" synthesis {"+" Synthesis Phase}]
     ["[1][0]" analysis {"+" Analysis}
-     ["[2][0]" primitive]]
+     ["[2][0]" primitive]
+     ["[2][0]" composite]]
     [///
      ["[0]" phase ("[1]#[0]" monad)]
      [reference {"+"}
@@ -58,12 +59,12 @@
       {///analysis.#Structure structure}
       (/.with_currying? false
         (case structure
-          {///analysis.#Variant variant}
+          {///composite.#Variant variant}
           (do phase.monad
-            [valueS (optimization' (value@ ///analysis.#value variant))]
-            (in (/.variant (with@ ///analysis.#value valueS variant))))
+            [valueS (optimization' (value@ ///composite.#value variant))]
+            (in (/.variant (with@ ///composite.#value valueS variant))))
 
-          {///analysis.#Tuple tuple}
+          {///composite.#Tuple tuple}
           (|> tuple
               (monad.each phase.monad optimization')
               (phase#each (|>> /.tuple)))))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/case.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/case.lux
index 29d478d0b..10d71f730 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/case.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/case.lux
@@ -22,7 +22,8 @@
   [//
    ["/" synthesis {"+" Path Synthesis Operation Phase}]
    ["[1][0]" analysis {"+" Pattern Match Analysis}
-    ["[2][0]" primitive]]
+    ["[2][0]" primitive]
+    ["[2][0]" composite]]
    [///
     ["[1]" phase ("[1]#[0]" monad)]
     ["[1][0]" reference
@@ -63,7 +64,7 @@
         /.with_new_local
         thenC)
 
-    {///analysis.#Complex {///analysis.#Variant [lefts right? value_pattern]}}
+    {///analysis.#Complex {///composite.#Variant [lefts right? value_pattern]}}
     (<| (///#each (|>> {/.#Seq {/.#Access {/.#Side (if right?
                                                      {.#Right lefts}
                                                      {.#Left lefts})}}}))
@@ -71,7 +72,7 @@
         (when> [(new> (not end?) [])] [(///#each ..clean_up)])
         thenC)
 
-    {///analysis.#Complex {///analysis.#Tuple tuple}}
+    {///analysis.#Complex {///composite.#Tuple tuple}}
     (let [tuple::last (-- (list.size tuple))]
       (list#mix (function (_ [tuple::lefts tuple::member] nextC)
                   (.case tuple::member
@@ -192,7 +193,7 @@
       <default>)))
 
 (def: (get patterns @selection)
-  (-> (///analysis.Tuple ///analysis.Pattern) Register (List /.Member))
+  (-> (///composite.Tuple ///analysis.Pattern) Register (List /.Member))
   (loop [lefts 0
          patterns patterns]
     (with_expansions [<failure> (as_is (list))
@@ -215,7 +216,7 @@
             (list <member>)
             <continue>)
 
-          {///analysis.#Complex {///analysis.#Tuple sub_patterns}}
+          {///analysis.#Complex {///composite.#Tuple sub_patterns}}
           (case (get sub_patterns @selection)
             {.#End}
             <continue>
@@ -264,7 +265,7 @@
     (.list)]])
 
 (def: .public (synthesize_get synthesize archive input patterns @member)
-  (-> Phase Archive Synthesis (///analysis.Tuple ///analysis.Pattern) Register (Operation Synthesis))
+  (-> Phase Archive Synthesis (///composite.Tuple ///analysis.Pattern) Register (Operation Synthesis))
   (case (..get patterns @member)
     {.#End}
     (..synthesize_case synthesize archive input (!get patterns @member))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/function.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/function.lux
index e2380b282..5e171165e 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/function.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/function.lux
@@ -19,7 +19,8 @@
   ["[0]" // "_"
    ["[1][0]" loop {"+" Transform}]
    ["//[1]" /// "_"
-    ["[1][0]" analysis {"+" Environment Analysis}]
+    ["[1][0]" analysis {"+" Environment Analysis}
+     ["[1]/[0]" composite]]
     ["/" synthesis {"+" Path Abstraction Synthesis Operation Phase}]
     [///
      [arity {"+" Arity}]
@@ -143,12 +144,12 @@
   (case expression
     {/.#Structure structure}
     (case structure
-      {////analysis.#Variant [lefts right? subS]}
+      {////analysis/composite.#Variant [lefts right? subS]}
       (|> subS
           (grow environment)
           (phase#each (|>> [lefts right?] /.variant)))
       
-      {////analysis.#Tuple membersS+}
+      {////analysis/composite.#Tuple membersS+}
       (|> membersS+
           (monad.each phase.monad (grow environment))
           (phase#each (|>> /.tuple))))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/loop.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
index 8b9273084..eea8ea951 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/loop.lux
@@ -12,7 +12,8 @@
      [number
       ["n" nat]]]]]
   [////
-   ["[0]" analysis {"+" Environment}]
+   ["[0]" analysis {"+" Environment}
+    ["[1]/[0]" composite]]
    ["/" synthesis {"+" Path Abstraction Synthesis}]
    [///
     [arity {"+" Arity}]
@@ -84,14 +85,14 @@
 
       {/.#Structure structure}
       (case structure
-        {analysis.#Variant variant}
+        {analysis/composite.#Variant variant}
         (do maybe.monad
-          [value' (|> variant (value@ analysis.#value) (again false))]
+          [value' (|> variant (value@ analysis/composite.#value) (again false))]
           (in (|> variant
-                  (with@ analysis.#value value')
+                  (with@ analysis/composite.#value value')
                   /.variant)))
         
-        {analysis.#Tuple tuple}
+        {analysis/composite.#Tuple tuple}
         (|> tuple
             (monad.each maybe.monad (again false))
             (maybe#each (|>> /.tuple))))
@@ -190,11 +191,11 @@
            matches (monad.each !
                                (function (_ match)
                                  (case match
-                                   (^ {/.#Structure {analysis.#Tuple (list when then)}})
+                                   (^ {/.#Structure {analysis/composite.#Tuple (list when then)}})
                                    (do !
                                      [when (again false when)
                                       then (again return? then)]
-                                     (in {/.#Structure {analysis.#Tuple (list when then)}}))
+                                     (in {/.#Structure {analysis/composite.#Tuple (list when then)}}))
 
                                    _
                                    (again false match)))
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/variable.lux b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/variable.lux
index 375919eca..79321ad28 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/variable.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/phase/synthesis/variable.lux
@@ -20,7 +20,8 @@
       ["n" nat]]]]]
   [////
    ["/" synthesis {"+" Path Synthesis}]
-   ["[0]" analysis]
+   ["[0]" analysis
+    ["[1]/[0]" composite]]
    [///
     [arity {"+" Arity}]
     ["[0]" reference
@@ -112,11 +113,11 @@
       
       {/.#Structure structure}
       {/.#Structure (case structure
-                      {analysis.#Variant [lefts right value]}
-                      {analysis.#Variant [lefts right (again value)]}
+                      {analysis/composite.#Variant [lefts right value]}
+                      {analysis/composite.#Variant [lefts right (again value)]}
                       
-                      {analysis.#Tuple tuple}
-                      {analysis.#Tuple (list#each again tuple)})}
+                      {analysis/composite.#Tuple tuple}
+                      {analysis/composite.#Tuple (list#each again tuple)})}
       
       {/.#Reference reference}
       (case reference
@@ -335,17 +336,17 @@
       
       {/.#Structure structure}
       (case structure
-        {analysis.#Variant [lefts right value]}
+        {analysis/composite.#Variant [lefts right value]}
         (do try.monad
           [[redundancy value] (optimization' [redundancy value])]
           (in [redundancy
-               {/.#Structure {analysis.#Variant [lefts right value]}}]))
+               {/.#Structure {analysis/composite.#Variant [lefts right value]}}]))
         
-        {analysis.#Tuple tuple}
+        {analysis/composite.#Tuple tuple}
         (do try.monad
           [[redundancy tuple] (..list_optimization optimization' [redundancy tuple])]
           (in [redundancy
-               {/.#Structure {analysis.#Tuple tuple}}])))
+               {/.#Structure {analysis/composite.#Tuple tuple}}])))
       
       {/.#Reference reference}
       (case reference
diff --git a/stdlib/source/library/lux/tool/compiler/language/lux/synthesis.lux b/stdlib/source/library/lux/tool/compiler/language/lux/synthesis.lux
index c27fa9a81..2bd2bd22e 100644
--- a/stdlib/source/library/lux/tool/compiler/language/lux/synthesis.lux
+++ b/stdlib/source/library/lux/tool/compiler/language/lux/synthesis.lux
@@ -1,38 +1,39 @@
 (.using
-  [library
-   [lux {"-" Primitive Scope i64}
-    [abstract
-     [monad {"+" do}]
-     [equivalence {"+" Equivalence}]
-     [hash {"+" Hash}]]
-    [control
-     [pipe {"+" case>}]
-     ["[0]" maybe]
-     ["[0]" exception {"+" exception:}]]
-    [data
-     ["[0]" sum]
-     ["[0]" product]
-     ["[0]" bit ("[1]#[0]" equivalence)]
-     ["[0]" text ("[1]#[0]" equivalence)
-      ["%" format {"+" Format format}]]
-     [collection
-      ["[0]" list ("[1]#[0]" functor)]
-      ["[0]" dictionary {"+" Dictionary}]]]
-    [math
-     [number
-      ["[0]" i64]
-      ["n" nat]
-      ["i" int]
-      ["f" frac]]]]]
-  [//
-   ["[0]" analysis {"+" Environment Composite Analysis}]
-   [phase
-    ["[0]" extension {"+" Extension}]]
-   [///
-    [arity {"+" Arity}]
-    ["[0]" phase]
-    ["[0]" reference {"+" Reference}
-     ["[0]" variable {"+" Register Variable}]]]])
+ [library
+  [lux {"-" Primitive Scope i64}
+   [abstract
+    [monad {"+" do}]
+    [equivalence {"+" Equivalence}]
+    [hash {"+" Hash}]]
+   [control
+    [pipe {"+" case>}]
+    ["[0]" maybe]
+    ["[0]" exception {"+" exception:}]]
+   [data
+    ["[0]" sum]
+    ["[0]" product]
+    ["[0]" bit ("[1]#[0]" equivalence)]
+    ["[0]" text ("[1]#[0]" equivalence)
+     ["%" format {"+" Format format}]]
+    [collection
+     ["[0]" list ("[1]#[0]" functor)]
+     ["[0]" dictionary {"+" Dictionary}]]]
+   [math
+    [number
+     ["[0]" i64]
+     ["n" nat]
+     ["i" int]
+     ["f" frac]]]]]
+ [//
+  ["[0]" analysis {"+" Environment Analysis}
+   ["[1]/[0]" composite {"+" Composite}]]
+  [phase
+   ["[0]" extension {"+" Extension}]]
+  [///
+   [arity {"+" Arity}]
+   ["[0]" phase]
+   ["[0]" reference {"+" Reference}
+    ["[0]" variable {"+" Register Variable}]]]])
 
 (type: .public Resolver
   (Dictionary Variable Variable))
@@ -238,8 +239,8 @@
           {<tag>}
           content)])]
 
-  [variant analysis.#Variant]
-  [tuple   analysis.#Tuple]
+  [variant analysis/composite.#Variant]
+  [tuple   analysis/composite.#Tuple]
   )
 
 (template [<name> <tag>]
@@ -350,12 +351,12 @@
 
     {#Structure structure}
     (case structure
-      {analysis.#Variant [lefts right? content]}
+      {analysis/composite.#Variant [lefts right? content]}
       (|> (%synthesis content)
           (format (%.nat lefts) " " (%.bit right?) " ")
           (text.enclosed ["{" "}"]))
       
-      {analysis.#Tuple members}
+      {analysis/composite.#Tuple members}
       (|> members
           (list#each %synthesis)
           (text.interposed " ")
@@ -775,7 +776,7 @@
         [[{<tag> reference'} {<tag> sample'}]
          (# <equivalence> = reference' sample')])
       ([#Primitive ..primitive_equivalence]
-       [#Structure (analysis.composite_equivalence =)]
+       [#Structure (analysis/composite.equivalence =)]
        [#Reference reference.equivalence]
        [#Control (control_equivalence =)]
        [#Extension (extension.equivalence =)])
@@ -799,7 +800,7 @@
           [{<tag> value}
            (# <hash> hash value)])
         ([#Primitive ..primitive_hash]
-         [#Structure (analysis.composite_hash again_hash)]
+         [#Structure (analysis/composite.hash again_hash)]
          [#Reference reference.hash]
          [#Control (..control_hash again_hash)]
          [#Extension (extension.hash again_hash)])))))
diff --git a/stdlib/source/library/lux/tool/compiler/meta/archive/dependency.lux b/stdlib/source/library/lux/tool/compiler/meta/archive/dependency.lux
index f3e1c6d83..7b0065dc4 100644
--- a/stdlib/source/library/lux/tool/compiler/meta/archive/dependency.lux
+++ b/stdlib/source/library/lux/tool/compiler/meta/archive/dependency.lux
@@ -23,7 +23,8 @@
      ["[0]" reference {"+" Constant}]
      [language
       [lux
-       ["[0]" analysis]
+       ["[0]" analysis
+        ["[1]/[0]" composite]]
        ["[0]" synthesis {"+" Synthesis Path}]
        ["[0]" generation {"+" Context Operation}]]]
      [meta
@@ -79,12 +80,12 @@
     
     {synthesis.#Structure value}
     (case value
-      {analysis.#Variant value}
+      {analysis/composite.#Variant value}
       (|> value
-          (value@ analysis.#value)
+          (value@ analysis/composite.#value)
           references)
       
-      {analysis.#Tuple value}
+      {analysis/composite.#Tuple value}
       (|> value
           (list#each references)
           list#conjoint))
diff --git a/stdlib/source/test/lux/target/ruby.lux b/stdlib/source/test/lux/target/ruby.lux
index 86a817703..7723cd776 100644
--- a/stdlib/source/test/lux/target/ruby.lux
+++ b/stdlib/source/test/lux/target/ruby.lux
@@ -5,7 +5,9 @@
    ["[0]" ffi]
    [abstract
     [monad {"+" do}]
-    ["[0]" predicate]]
+    ["[0]" predicate]
+    [\\specification
+     ["$[0]" equivalence]]]
    [control
     ["[0]" maybe ("[1]#[0]" functor)]
     ["[0]" try {"+" Try} ("[1]#[0]" functor)]]
@@ -306,7 +308,7 @@
                                      (|> ($_ /.then
                                              (/.set (list $foreign) (/.+ $foreign $foreign))
                                              (/.return $foreign))
-                                         (/.lambda {.#None} (list $foreign))
+                                         [(list $foreign)] (/.lambda {.#None})
                                          (/.apply_lambda/* (list (/.float float/0))))))
                 ))
         (_.cover [/.Access]
@@ -316,7 +318,7 @@
                                             (/.set (list $foreign) (/.array (list $foreign)))
                                             (/.set (list @) (/.+ @ @))
                                             (/.return @))
-                                        (/.lambda {.#None} (list $foreign))
+                                        [(list $foreign)] (/.lambda {.#None})
                                         (/.apply_lambda/* (list (/.float float/0))))))
                       (expression (|>> (:as Frac) (f.= (f.+ float/0 float/0)))
                                   (let [@ (/.item field $foreign)]
@@ -324,7 +326,7 @@
                                             (/.set (list $foreign) (/.hash (list [field $foreign])))
                                             (/.set (list @) (/.+ @ @))
                                             (/.return @))
-                                        (/.lambda {.#None} (list $foreign))
+                                        [(list $foreign)] (/.lambda {.#None})
                                         (/.apply_lambda/* (list (/.float float/0))))))
                       ))
         )))
@@ -359,7 +361,7 @@
                                                     (/.set (list $inner_index) (/.+ (/.int +1) $inner_index))
                                                     ))
                                        (/.return $output))
-                                   (/.lambda {.#None} (list $input))
+                                   [(list $input)] (/.lambda {.#None})
                                    (/.apply_lambda/* (list (/.int input)))))))
         (_.cover [/.next]
                  (let [expected (i.* (.int (n.- expected_inner_iterations full_inner_iterations)) input)]
@@ -375,7 +377,7 @@
                                                     (/.set (list $output) (/.+ $input $output))
                                                     ))
                                        (/.return $output))
-                                   (/.lambda {.#None} (list $input))
+                                   [(list $input)] (/.lambda {.#None})
                                    (/.apply_lambda/* (list (/.int input)))))))
         )))
 
@@ -400,7 +402,7 @@
                                                   (/.set (list $index) (/.+ (/.int +1) $index))
                                                   ))
                                      (/.return $output))
-                                 (/.lambda {.#None} (list $input))
+                                 [(list $input)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list (/.int input))))))
         (_.cover [/.for_in]
                  (expression (|>> (:as Int) (i.= expected))
@@ -409,7 +411,7 @@
                                      (/.for_in $index (/.array (list.repeated iterations (/.int input)))
                                                (/.set (list $output) (/.+ $index $output)))
                                      (/.return $output))
-                                 (/.lambda {.#None} (list $input))
+                                 [(list $input)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list (/.int input))))))
         ..test|label
         )))
@@ -420,13 +422,19 @@
     [expected random.safe_frac
      dummy (random.only (|>> (f.= expected) not)
                         random.safe_frac)
-     $ex (# ! each /.local (random.ascii/lower 10))]
+     $ex (# ! each /.local (random.ascii/lower 10))
+
+     expected_tag random.int
+     dummy_tag (random.only (|>> (i.= expected_tag) not)
+                            random.int)
+     .let [expected_tag (/.int expected_tag)
+           dummy_tag (/.int dummy_tag)]]
     ($_ _.and
         (_.cover [/.begin]
                  (expression (|>> (:as Frac) (f.= expected))
                              (|> (/.begin (/.return (/.float expected))
                                           (list [(list) $ex (/.return (/.float dummy))]))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         (_.cover [/.Rescue /.throw/1]
                  (expression (|>> (:as Frac) (f.= expected))
@@ -434,8 +442,37 @@
                                               (/.throw/1 (/.string ""))
                                               (/.return (/.float dummy)))
                                           (list [(list) $ex (/.return (/.float expected))]))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
+                                 (/.apply_lambda/* (list)))))
+        (_.cover [/.raise]
+                 (expression (|>> (:as Frac) (f.= expected))
+                             (|> (/.begin ($_ /.then
+                                              (/.statement (/.raise (/.string "")))
+                                              (/.return (/.float dummy)))
+                                          (list [(list) $ex (/.return (/.float expected))]))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
+        (_.cover [/.catch /.throw/2]
+                 (and (expression (|>> (:as Frac) (f.= expected))
+                                  (<| (/.apply_lambda/* (list))
+                                      (/.lambda {.#None}) [(list)]
+                                      /.return
+                                      (/.catch expected_tag) [(list)]
+                                      (/.throw/2 expected_tag (/.float expected))))
+                      (expression (|>> (:as Frac) (f.= expected))
+                                  (<| (/.apply_lambda/* (list))
+                                      (/.lambda {.#None}) [(list)]
+                                      /.return
+                                      (/.catch expected_tag) [(list)]
+                                      /.statement (/.catch dummy_tag) [(list)]
+                                      (/.throw/2 expected_tag (/.float expected))))
+                      (expression (|>> (:as Frac) (f.= expected))
+                                  (<| (/.apply_lambda/* (list))
+                                      (/.lambda {.#None}) [(list)]
+                                      /.return
+                                      (/.catch dummy_tag) [(list)]
+                                      /.statement (/.catch expected_tag) [(list)]
+                                      (/.throw/2 expected_tag (/.float expected))))))
         )))
 
 (def: test|function
@@ -456,18 +493,18 @@
         (_.cover [/.lambda /.return]
                  (and (expression (|>> (:as Frac) (f.= float/0))
                                   (|> (/.return (/.float float/0))
-                                      (/.lambda {.#None} (list))
+                                      [(list)] (/.lambda {.#None})
                                       (/.apply_lambda/* (list))))
                       (expression (|>> (:as Frac) f.nat (n.= iterations))
-                                  (|> (/.lambda {.#Some $self} (list $arg/0)
-                                                (/.return (/.? (/.< (/.int (.int iterations)) $arg/0)
-                                                               (/.apply_lambda/* (list (/.+ (/.int +1) $arg/0)) $self)
-                                                               $arg/0)))
+                                  (|> (/.return (/.? (/.< (/.int (.int iterations)) $arg/0)
+                                                     (/.apply_lambda/* (list (/.+ (/.int +1) $arg/0)) $self)
+                                                     $arg/0))
+                                      [(list $arg/0)] (/.lambda {.#Some $self})
                                       (/.apply_lambda/* (list (/.int +0)))))))
         (_.cover [/.apply_lambda/*]
                  (expression (|>> (:as Frac) (f.= ($_ f.+ float/0 float/1 float/2)))
                              (|> (/.return ($_ /.+ $arg/0 $arg/1 $arg/2))
-                                 (/.lambda {.#None} (list $arg/0 $arg/1 $arg/2))
+                                 [(list $arg/0 $arg/1 $arg/2)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list (/.float float/0) (/.float float/1) (/.float float/2))))))
         (_.cover [/.function]
                  (expression (|>> (:as Frac) f.nat (n.= iterations))
@@ -477,7 +514,7 @@
                                                       (/.apply/1 $self (/.+ (/.int +1) $arg/0))
                                                       $arg/0)))
                                      (/.return (/.apply/1 $self (/.int +0))))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         (_.cover [/.apply/1]
                  (expression (|>> (:as Frac) (f.= float/0))
@@ -485,7 +522,7 @@
                                      (/.function $self (list $arg/0)
                                        (/.return $arg/0))
                                      (/.return (/.apply/1 $self (/.float float/0))))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         (_.cover [/.apply/2]
                  (expression (|>> (:as Frac) (f.= ($_ f.+ float/0 float/1)))
@@ -493,15 +530,7 @@
                                      (/.function $self (list $arg/0 $arg/1)
                                        (/.return ($_ /.+ $arg/0 $arg/1)))
                                      (/.return (/.apply/2 $self (/.float float/0) (/.float float/1))))
-                                 (/.lambda {.#None} (list))
-                                 (/.apply_lambda/* (list)))))
-        (_.cover [/.apply/3]
-                 (expression (|>> (:as Frac) (f.= ($_ f.+ float/0 float/1 float/2)))
-                             (|> ($_ /.then
-                                     (/.function $self (list $arg/0 $arg/1 $arg/2)
-                                       (/.return ($_ /.+ $arg/0 $arg/1 $arg/2)))
-                                     (/.return (/.apply/3 $self (/.float float/0) (/.float float/1) (/.float float/2))))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         (_.cover [/.apply/*]
                  (expression (|>> (:as Frac) (f.= ($_ f.+ float/0 float/1 float/2)))
@@ -509,7 +538,7 @@
                                      (/.function $self (list $arg/0 $arg/1 $arg/2)
                                        (/.return ($_ /.+ $arg/0 $arg/1 $arg/2)))
                                      (/.return (/.apply/* (list (/.float float/0) (/.float float/1) (/.float float/2)) {.#None} $self)))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         ... (_.cover [/.new]
         ...          (let [$this (/.local "this")]
@@ -544,7 +573,7 @@
                              (|> (/.if (/.bool ???)
                                    (/.return (/.float float/0))
                                    (/.return (/.float float/1)))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         (_.cover [/.when]
                  (expression (|>> (:as Frac) (f.= (if ??? float/0 float/1)))
@@ -552,7 +581,7 @@
                                      (/.when (/.bool ???)
                                              (/.return (/.float float/0)))
                                      (/.return (/.float float/1)))
-                                 (/.lambda {.#None} (list))
+                                 [(list)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list)))))
         )))
 
@@ -571,19 +600,20 @@
                              (|> ($_ /.then
                                      (/.statement (/.+ $arg/0 $arg/0))
                                      (/.return $arg/0))
-                                 (/.lambda {.#None} (list $arg/0))
+                                 [(list $arg/0)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list (/.float float/0))))))
         (_.cover [/.then]
                  (expression (|>> (:as Frac) (f.= float/0))
                              (|> ($_ /.then
                                      (/.return $arg/0)
                                      (/.return $arg/1))
-                                 (/.lambda {.#None} (list $arg/0 $arg/1))
+                                 [(list $arg/0 $arg/1)] (/.lambda {.#None})
                                  (/.apply_lambda/* (list (/.float float/0) (/.float float/1))))))
         ..test|exception
-        ..test|function
         ..test|branching
         ..test|loop
+        (_.for [/.Block]
+               ..test|function)
         (_.for [/.Location]
                ..test/location)
         )))
@@ -632,10 +662,13 @@
     (<| (_.covering /._)
         (_.for [/.Code])
         ($_ _.and
+            (_.for [/.equivalence]
+                   ($equivalence.spec /.equivalence ..random_expression))
+            
             (_.cover [/.code /.manual]
                      (|> (/.manual (/.code expected))
                          (: /.Expression)
-                         (# /.code_equivalence = expected)))
+                         (# /.equivalence = expected)))
             (_.for [/.Expression]
                    ..test|expression)
             (_.for [/.Statement]
diff --git a/stdlib/source/test/lux/tool.lux b/stdlib/source/test/lux/tool.lux
index e2cbc50b6..4e3bad586 100644
--- a/stdlib/source/test/lux/tool.lux
+++ b/stdlib/source/test/lux/tool.lux
@@ -11,7 +11,8 @@
     [lux
      ... ["[1][0]" syntax]
      ["[1][0]" analysis "_"
-      ["[1]/[0]" primitive]]
+      ["[1]/[0]" primitive]
+      ["[1]/[0]" composite]]
      ... [phase
      ...  ["[1][0]" analysis]
      ...  ["[1][0]" synthesis]]
@@ -25,6 +26,7 @@
       /version.test
       /reference.test
       /analysis/primitive.test
+      /analysis/composite.test
       ... /syntax.test
       ... /analysis.test
       ... /synthesis.test
diff --git a/stdlib/source/test/lux/tool/compiler/language/lux/analysis/composite.lux b/stdlib/source/test/lux/tool/compiler/language/lux/analysis/composite.lux
new file mode 100644
index 000000000..8c74718b8
--- /dev/null
+++ b/stdlib/source/test/lux/tool/compiler/language/lux/analysis/composite.lux
@@ -0,0 +1,76 @@
+(.using
+ [library
+  [lux "*"
+   ["_" test {"+" Test}]
+   [abstract
+    [monad {"+" do}]
+    [\\specification
+     ["$[0]" equivalence]
+     ["$[0]" hash]]]
+   [data
+    ["[0]" bit ("[1]#[0]" equivalence)]
+    ["[0]" text ("[1]#[0]" equivalence)
+     ["%" format {"+" format}]]]
+   [math
+    ["[0]" random {"+" Random} ("[1]#[0]" monad)]
+    [number
+     ["n" nat]]]]]
+ [\\library
+  ["[0]" /]])
+
+(def: test|tag
+  Test
+  (do [! random.monad]
+    [multiplicity (# ! each (n.max 2) random.nat)
+     tag (# ! each (n.% multiplicity) random.nat)
+     lefts random.nat
+     right? random.bit]
+    ($_ _.and
+        (_.cover [/.tag /.lefts]
+                 (and (|> lefts
+                          (/.tag right?)
+                          (/.lefts right?)
+                          (n.= lefts))
+                      (|> tag
+                          (/.lefts right?)
+                          (/.tag right?)
+                          (n.= tag))))
+        (_.cover [/.choice]
+                 (let [[lefts right?] (/.choice multiplicity tag)]
+                   (if right?
+                     (n.= (-- tag) lefts)
+                     (n.= tag lefts))))
+        )))
+
+(def: .public (random multiplicity it)
+  (All (_ a)
+    (-> Nat (Random a) (Random (/.Composite a))))
+  ($_ random.or
+      ($_ random.and
+          (random#each (n.% (-- multiplicity)) random.nat)
+          random.bit
+          it)
+      (random.list multiplicity it)
+      ))
+
+(def: .public test
+  Test
+  (let [random (..random 3 random.nat)]
+    (<| (_.covering /._)
+        (_.for [/.Composite /.Variant /.Tuple])
+        ($_ _.and
+            (_.for [/.equivalence]
+                   ($equivalence.spec (/.equivalence n.equivalence) random))
+            (_.for [/.hash]
+                   ($hash.spec (/.hash n.hash) random))
+
+            (_.for [/.Tag]
+                   ..test|tag)
+            
+            (do random.monad
+              [left random
+               right random]
+              (_.cover [/.format]
+                       (bit#= (# (/.equivalence n.equivalence) = left right)
+                              (text#= (/.format %.nat left) (/.format %.nat right)))))
+            ))))