5 files changed, 13 insertions, 5 deletions
diff --git a/stdlib/source/lux/control/monoid.lux b/stdlib/source/lux/control/monoid.lux
index 53f91474f..6634445a6 100644
--- a/stdlib/source/lux/control/monoid.lux
+++ b/stdlib/source/lux/control/monoid.lux
@@ -1,6 +1,5 @@
 (;module: lux)
 
-## Signatures
 (sig: #export (Monoid a)
   {#;doc "A way to compose values.
 
@@ -9,3 +8,12 @@
      identity)
   (: (-> a a a)
      compose))
+
+(def: #export (compose Monoid<l> Monoid<r>)
+  (All [l r] (-> (Monoid l) (Monoid r) (Monoid [l r])))
+  (struct (def: identity
+            [(:: Monoid<l> identity) (:: Monoid<r> identity)])
+          
+          (def: (compose [lL rL] [lR rR])
+            [(:: Monoid<l> compose lL lR)
+             (:: Monoid<r> compose rL rR)])))
diff --git a/stdlib/source/lux/data/bool.lux b/stdlib/source/lux/data/bool.lux
index b07d3c8df..c5b345ce1 100644
--- a/stdlib/source/lux/data/bool.lux
+++ b/stdlib/source/lux/data/bool.lux
@@ -1,6 +1,6 @@
 (;module:
   lux
-  (lux (control monoid
+  (lux (control [monoid #+ Monoid]
                 [eq #+ Eq]
                 hash
                 codec)))
diff --git a/stdlib/source/lux/data/coll/list.lux b/stdlib/source/lux/data/coll/list.lux
index 5db72e77e..cab5479be 100644
--- a/stdlib/source/lux/data/coll/list.lux
+++ b/stdlib/source/lux/data/coll/list.lux
@@ -1,6 +1,6 @@
 (;module:
   lux
-  (lux (control monoid
+  (lux (control [monoid #+ Monoid]
                 ["F" functor]
                 ["A" applicative]
                 ["M" monad #+ do Monad]
diff --git a/stdlib/source/lux/data/number.lux b/stdlib/source/lux/data/number.lux
index 769561b83..332ce6562 100644
--- a/stdlib/source/lux/data/number.lux
+++ b/stdlib/source/lux/data/number.lux
@@ -1,7 +1,7 @@
 (;module: {#;doc "Implementations of common structures for Lux's primitive number types."}
   lux
   (lux (control number
-                monoid
+                [monoid #+ Monoid]
                 [eq #+ Eq]
                 hash
                 [order]
diff --git a/stdlib/source/lux/data/text.lux b/stdlib/source/lux/data/text.lux
index dd25a1359..835d55fd1 100644
--- a/stdlib/source/lux/data/text.lux
+++ b/stdlib/source/lux/data/text.lux
@@ -1,6 +1,6 @@
 (;module:
   lux
-  (lux (control monoid
+  (lux (control [monoid #+ Monoid]
                 [eq #+ Eq]
                 [order]
                 ["M" monad #+ do Monad]