1. Type-checking/inference now more principled, and the implementation is better. 2. Changed most tactics to context tactics.

11 files changed, 285 insertions, 505 deletions

diff --git a/spartan/core/Spartan.thy b/spartan/core/Spartan.thy
index 1b9093b..a4ad300 100644
--- a/spartan/core/Spartan.thy
+++ b/spartan/core/Spartan.thy
@@ -79,16 +79,16 @@ axiomatization
   lt_trans: "i < j \<Longrightarrow> j < k \<Longrightarrow> i < k"
 
 axiomatization U :: \<open>lvl \<Rightarrow> o\<close> where
-  U_hierarchy: "i < j \<Longrightarrow> U i: U j" and
-  U_cumulative: "A: U i \<Longrightarrow> i < j \<Longrightarrow> A: U j"
+  Ui_in_Uj: "i < j \<Longrightarrow> U i: U j" and
+  in_Uj_if_in_Ui: "A: U i \<Longrightarrow> i < j \<Longrightarrow> A: U j"
 
-lemma U_in_U:
+lemma Ui_in_USi:
   "U i: U (S i)"
-  by (rule U_hierarchy, rule lt_S)
+  by (rule Ui_in_Uj, rule lt_S)
 
-lemma lift_U:
+lemma in_USi_if_in_Ui:
   "A: U i \<Longrightarrow> A: U (S i)"
-  by (erule U_cumulative, rule lt_S)
+  by (erule in_Uj_if_in_Ui, rule lt_S)
 
 
 subsection \<open>\<Prod>-type\<close>
@@ -199,70 +199,61 @@ consts "rhs" :: \<open>'a\<close> ("..")
 
 ML_file \<open>congruence.ML\<close>
 
-subsection \<open>Theorem attributes, type-checking and proof methods\<close>
+subsection \<open>Proof methods and type-checking/inference\<close>
 
-named_theorems intros and comps
+named_theorems form and intro and intros and comp
+\<comment> \<open>`intros` stores the introduction rule variants used by the
+  `intro` and `intros` methods.\<close>
 
 ML_file \<open>elimination.ML\<close> \<comment> \<open>elimination rules\<close>
 ML_file \<open>cases.ML\<close> \<comment> \<open>case reasoning rules\<close>
 
 lemmas
-  [intros] = anno PiF PiI SigF SigI and
-  [elims "?f"] = PiE and
-  [elims "?p"] = SigE and
-  [comps] = beta Sig_comp and
+  [form] = PiF SigF and
+  [intro] = PiI SigI and
+  [intros] = PiI[rotated] SigI and
+  [elim "?f"] = PiE and
+  [elim "?p"] = SigE and
+  [comp] = beta Sig_comp and
   [cong] = Pi_cong lam_cong Sig_cong
 
 ML_file \<open>typechecking.ML\<close>
-ML_file \<open>tactics2.ML\<close>
 ML_file \<open>tactics.ML\<close>
 
-method_setup assumptions =
-  \<open>Scan.succeed (fn ctxt => SIMPLE_METHOD (
-    CHANGED (TRYALL (assumptions_tac ctxt))))\<close>
+method_setup typechk =
+  \<open>Scan.succeed (K (CONTEXT_METHOD (
+    CHEADGOAL o Types.check_infer)))\<close>
 
 method_setup known =
-  \<open>Scan.succeed (fn ctxt => SIMPLE_METHOD (
-    CHANGED (TRYALL (known_tac ctxt))))\<close>
+  \<open>Scan.succeed (K (CONTEXT_METHOD (
+    CHEADGOAL o Types.known_ctac)))\<close>
+
+method_setup rule =
+  \<open>Attrib.thms >> (fn ths => K (CONTEXT_METHOD (
+    CHEADGOAL o SIDE_CONDS (rule_ctac ths))))\<close>
+
+method_setup dest =
+  \<open>Scan.lift (Scan.option (Args.parens Parse.int))
+    -- Attrib.thms >> (fn (n_opt, ths) => K (CONTEXT_METHOD (
+      CHEADGOAL o SIDE_CONDS (dest_ctac n_opt ths))))\<close>
 
 method_setup intro =
-  \<open>Scan.succeed (fn ctxt => SIMPLE_METHOD (HEADGOAL (intro_tac ctxt)))\<close>
+  \<open>Scan.succeed (K (CONTEXT_METHOD (
+    CHEADGOAL o SIDE_CONDS (intro_ctac))))\<close>
 
 method_setup intros =
-  \<open>Scan.succeed (fn ctxt => SIMPLE_METHOD (HEADGOAL (intros_tac ctxt)))\<close>
+  \<open>Scan.succeed (K (CONTEXT_METHOD (
+    CHEADGOAL o SIDE_CONDS (CREPEAT o intro_ctac))))\<close>
 
 method_setup elim =
-  \<open>Scan.repeat Args.term >> (fn tms => fn ctxt =>
-    CONTEXT_METHOD (K (elim_context_tac tms ctxt 1)))\<close>
+  \<open>Scan.repeat Args.term >> (fn tms => K (CONTEXT_METHOD (
+    CHEADGOAL o SIDE_CONDS (elim_ctac tms))))\<close>
 
 method elims = elim+
 
 method_setup cases =
-  \<open>Args.term >> (fn tm => fn ctxt => SIMPLE_METHOD' (cases_tac tm ctxt))\<close>
-
-(*This could possibly use additional simplification hints via a simp: modifier*)
-method_setup typechk' =
-  \<open>Scan.succeed (fn ctxt => SIMPLE_METHOD' (
-    SIDE_CONDS (typechk_tac ctxt) ctxt))
-    (* CHANGED (ALLGOALS (TRY o typechk_tac ctxt)))) *)\<close>
-
-method_setup rule' =
-  \<open>Attrib.thms >> (fn ths => fn ctxt =>
-    SIMPLE_METHOD (HEADGOAL (SIDE_CONDS (rule_tac ths ctxt) ctxt)))\<close>
-
-method_setup dest =
-  \<open>Scan.lift (Scan.option (Args.parens Parse.int)) -- Attrib.thms
-    >> (fn (opt_n, ths) => fn ctxt =>
-        SIMPLE_METHOD (HEADGOAL (SIDE_CONDS (dest_tac opt_n ths ctxt) ctxt)))\<close>
-
-(*NEW*)
-method_setup typechk =
-  \<open>Scan.succeed (K (CONTEXT_METHOD (
-    CHEADGOAL o Types.check_infer)))\<close>
-
-method_setup rule =
-  \<open>Attrib.thms >> (fn ths => K (CONTEXT_METHOD (
-    CHEADGOAL o Tactics2.SIDE_CONDS (Tactics2.rule_tac ths))))\<close>
+  \<open>Args.term >> (fn tm => K (CONTEXT_METHOD (
+    CHEADGOAL o SIDE_CONDS (cases_ctac tm))))\<close>
 
 
 subsection \<open>Reflexivity\<close>
@@ -270,14 +261,13 @@ subsection \<open>Reflexivity\<close>
 named_theorems refl
 method refl = (rule refl)
 
-subsection \<open>Trivial proofs modulo typechecking\<close>
+subsection \<open>Trivial proofs (modulo automatic discharge of side conditions)\<close>
 
 method_setup this =
-  \<open>Scan.succeed (fn ctxt => METHOD (
-    EVERY o map (HEADGOAL o
-      (fn ths => SIDE_CONDS (resolve_tac ctxt ths) ctxt) o
-      single)
-    ))\<close>
+  \<open>Scan.succeed (K (CONTEXT_METHOD (fn facts =>
+    CHEADGOAL (SIDE_CONDS
+      (CONTEXT_TACTIC' (fn ctxt => resolve_tac ctxt facts))
+      facts))))\<close>
 
 subsection \<open>Rewriting\<close>
 
@@ -298,7 +288,7 @@ lemma eta_expand:
 lemma rewr_imp:
   assumes "PROP A \<equiv> PROP B"
   shows "(PROP A \<Longrightarrow> PROP C) \<equiv> (PROP B \<Longrightarrow> PROP C)"
-  apply (rule Pure.equal_intr_rule)
+  apply (Pure.rule Pure.equal_intr_rule)
   apply (drule equal_elim_rule2[OF assms]; assumption)
   apply (drule equal_elim_rule1[OF assms]; assumption)
   done
@@ -316,9 +306,11 @@ ML_file \<open>~~/src/HOL/Library/cconv.ML\<close>
 ML_file \<open>rewrite.ML\<close>
 
 \<comment> \<open>\<open>reduce\<close> computes terms via judgmental equalities\<close>
-setup \<open>map_theory_simpset (fn ctxt => ctxt addSolver (mk_solver "" typechk_tac))\<close>
+setup \<open>map_theory_simpset (fn ctxt =>
+  ctxt addSolver (mk_solver "" (fn ctxt' =>
+    NO_CONTEXT_TACTIC ctxt' o Types.check_infer (Simplifier.prems_of ctxt'))))\<close>
 
-method reduce uses add = (simp add: comps add | subst comps)+
+method reduce uses add = changed \<open>((simp add: comp add | sub comp); typechk?)+\<close>
 
 subsection \<open>Implicits\<close>
 
@@ -387,11 +379,8 @@ lemma refine_codomain:
 lemma lift_universe_codomain:
   assumes "A: U i" "f: A \<rightarrow> U j"
   shows "f: A \<rightarrow> U (S j)"
-  (*FIXME: Temporary; should be fixed once all methods are rewritten to use
-    the new typechk*)
-  apply (Pure.rule refine_codomain, typechk, typechk)
-  apply (Pure.rule lift_U, typechk)
-  done
+  using in_USi_if_in_Ui[of "f {}"]
+  by (rule refine_codomain)
 
 subsection \<open>Function composition\<close>
 
@@ -413,7 +402,7 @@ lemma funcompI [typechk]:
     "g \<circ>\<^bsub>A\<^esub> f: \<Prod>x: A. C (f x)"
   unfolding funcomp_def by typechk
 
-lemma funcomp_assoc [comps]:
+lemma funcomp_assoc [comp]:
   assumes
     "f: A \<rightarrow> B"
     "g: B \<rightarrow> C"
@@ -423,7 +412,7 @@ lemma funcomp_assoc [comps]:
     "(h \<circ>\<^bsub>B\<^esub> g) \<circ>\<^bsub>A\<^esub> f \<equiv> h \<circ>\<^bsub>A\<^esub> g \<circ>\<^bsub>A\<^esub> f"
   unfolding funcomp_def by reduce
 
-lemma funcomp_lambda_comp [comps]:
+lemma funcomp_lambda_comp [comp]:
   assumes
     "A: U i"
     "\<And>x. x: A \<Longrightarrow> b x: B"
@@ -432,7 +421,7 @@ lemma funcomp_lambda_comp [comps]:
     "(\<lambda>x: B. c x) \<circ>\<^bsub>A\<^esub> (\<lambda>x: A. b x) \<equiv> \<lambda>x: A. c (b x)"
   unfolding funcomp_def by reduce
 
-lemma funcomp_apply_comp [comps]:
+lemma funcomp_apply_comp [comp]:
   assumes
     "f: A \<rightarrow> B" "g: \<Prod>x: B. C x"
     "x: A"
@@ -454,22 +443,22 @@ abbreviation id where "id A \<equiv> \<lambda>x: A. x"
 
 lemma
   id_type[typechk]: "A: U i \<Longrightarrow> id A: A \<rightarrow> A" and
-  id_comp [comps]: "x: A \<Longrightarrow> (id A) x \<equiv> x" \<comment> \<open>for the occasional manual rewrite\<close>
-  by reduce
+  id_comp [comp]: "x: A \<Longrightarrow> (id A) x \<equiv> x" \<comment> \<open>for the occasional manual rewrite\<close>
+  by reduce+
 
-lemma id_left [comps]:
+lemma id_left [comp]:
   assumes "f: A \<rightarrow> B" "A: U i" "B: U i"
   shows "(id B) \<circ>\<^bsub>A\<^esub> f \<equiv> f"
   by (subst eta_exp[of f]) (reduce, rule eta)
 
-lemma id_right [comps]:
+lemma id_right [comp]:
   assumes "f: A \<rightarrow> B" "A: U i" "B: U i"
   shows "f \<circ>\<^bsub>A\<^esub> (id A) \<equiv> f"
   by (subst eta_exp[of f]) (reduce, rule eta)
 
 lemma id_U [typechk]:
   "id (U i): U i \<rightarrow> U i"
-  by typechk (fact U_in_U)
+  by typechk (rule Ui_in_USi) (*FIXME: Add annotation rule to typechecker*)
 
 
 section \<open>Pairs\<close>
@@ -482,7 +471,7 @@ lemma fst_type [typechk]:
   shows "fst A B: (\<Sum>x: A. B x) \<rightarrow> A"
   unfolding fst_def by typechk
 
-lemma fst_comp [comps]:
+lemma fst_comp [comp]:
   assumes
     "a: A"
     "b: B a"
@@ -496,10 +485,10 @@ lemma snd_type [typechk]:
   shows "snd A B: \<Prod>p: \<Sum>x: A. B x. B (fst A B p)"
   unfolding snd_def by typechk reduce
 
-lemma snd_comp [comps]:
+lemma snd_comp [comp]:
   assumes "a: A" "b: B a" "A: U i" "\<And>x. x: A \<Longrightarrow> B x: U i"
   shows "snd A B <a, b> \<equiv> b"
-  unfolding snd_def by reduce
+  unfolding snd_def by reduce+
 
 subsection \<open>Notation\<close>
 
@@ -509,7 +498,7 @@ definition fst_i ("fst")
 definition snd_i ("snd")
   where [implicit]: "snd \<equiv> Spartan.snd ? ?"
 
-no_translations
+translations
   "fst" \<leftharpoondown> "CONST Spartan.fst A B"
   "snd" \<leftharpoondown> "CONST Spartan.snd A B"
 
@@ -520,22 +509,14 @@ Lemma fst [typechk]:
     "p: \<Sum>x: A. B x"
     "A: U i" "\<And>x. x: A \<Longrightarrow> B x: U i"
   shows "fst p: A"
-  \<comment> \<open>This can't be solved by a single application of `typechk`; it needs
-    multiple (two) passes. Something to do with constraint/subgoal reordering.\<close>
-  apply (Pure.rule elims)
-    apply (Pure.rule typechk)
-    apply known [1]
-    defer \<comment> \<open>The deferred subgoal is an inhabitation problem.\<close>
-    apply known [1]
-  by known
-    
+  by typechk    
 
 Lemma snd [typechk]:
   assumes
     "p: \<Sum>x: A. B x"
     "A: U i" "\<And>x. x: A \<Longrightarrow> B x: U i"
   shows "snd p: B (fst p)"
-  by typechk+
+  by typechk
 
 method fst for p::o = rule fst[of p]
 method snd for p::o = rule snd[of p]
diff --git a/spartan/core/context_tactical.ML b/spartan/core/context_tactical.ML
index 78991a9..a5159f6 100644
--- a/spartan/core/context_tactical.ML
+++ b/spartan/core/context_tactical.ML
@@ -11,6 +11,7 @@ structure Context_Tactical:
 sig
 
 type context_tactic' = int -> context_tactic
+val CONTEXT_TACTIC': (Proof.context -> int -> tactic) -> context_tactic'
 val all_ctac: context_tactic
 val no_ctac: context_tactic
 val print_ctac: (Proof.context -> string) -> context_tactic
@@ -25,16 +26,21 @@ val CREPEAT: context_tactic -> context_tactic
 val CFILTER: (context_state -> bool) -> context_tactic -> context_tactic
 val CCHANGED: context_tactic -> context_tactic
 val CTHEN_ALL_NEW: context_tactic' * context_tactic' -> context_tactic'
+val CREPEAT_IN_RANGE: int -> int -> context_tactic' -> context_tactic
 val CREPEAT_ALL_NEW: context_tactic' -> context_tactic'
 val CTHEN_ALL_NEW_FWD: context_tactic' * context_tactic' -> context_tactic'
 val CREPEAT_ALL_NEW_FWD: context_tactic' -> context_tactic'
 val CHEADGOAL: context_tactic' -> context_tactic
 val CALLGOALS: context_tactic' -> context_tactic
+val CSOMEGOAL: context_tactic' -> context_tactic
+val CRANGE: context_tactic' list -> context_tactic'
 
 end = struct
 
 type context_tactic' = int -> context_tactic
 
+fun CONTEXT_TACTIC' tac i (ctxt, st) = TACTIC_CONTEXT ctxt ((tac ctxt i) st)
+
 val all_ctac = Seq.make_results o Seq.single
 val no_ctac = K Seq.empty
 fun print_ctac f (ctxt, st) = CONTEXT_TACTIC (print_tac ctxt (f ctxt)) (ctxt, st)
@@ -87,26 +93,34 @@ local
 
   (*By Peter Lammich: apply tactic to subgoals in interval in a forward manner,
     skipping over emerging subgoals*)
-  fun INTERVAL_FWD ctac l u (cst as (_, st)) =
-    if l > u then all_ctac cst
+  fun INTERVAL_FWD ctac l u (cst as (_, st)) = cst |>
+    (if l > u then all_ctac
     else (ctac l CTHEN (fn cst' as (_, st') =>
       let val ofs = Thm.nprems_of st' - Thm.nprems_of st in
         if ofs < ~1
         then raise THM (
           "INTERVAL_FWD: tactic solved more than one goal", ~1, [st, st'])
         else INTERVAL_FWD ctac (l + 1 + ofs) (u + ofs) cst'
-      end)) cst
+      end)))
 in
 
 fun (ctac1 CTHEN_ALL_NEW ctac2) i (cst as (_, st)) =
   cst |> (ctac1 i CTHEN (fn cst' as (_, st') =>
-    cst' |> INTERVAL ctac2 i (i + Thm.nprems_of st' - Thm.nprems_of st)))
+    INTERVAL ctac2 i (i + Thm.nprems_of st' - Thm.nprems_of st) cst'))
 
 (*By Peter Lammich: apply ctac2 to all subgoals emerging from ctac1, in forward
   manner*)
 fun (ctac1 CTHEN_ALL_NEW_FWD ctac2) i (cst as (_, st)) =
   cst |> (ctac1 i CTHEN (fn cst' as (_, st') =>
-    cst' |> INTERVAL_FWD ctac2 i (i + Thm.nprems_of st' - Thm.nprems_of st)))
+    INTERVAL_FWD ctac2 i (i + Thm.nprems_of st' - Thm.nprems_of st) cst'))
+
+(*Repeatedly apply ctac to the i-th until the k-th-from-last subgoals
+  (i.e. leave the last k subgoals alone), until no more changes appear in the
+  goal state.*)
+fun CREPEAT_IN_RANGE i k ctac =
+  let fun interval_ctac (cst as (_, st)) =
+    INTERVAL_FWD ctac i (Thm.nprems_of st - k) cst
+  in CREPEAT (CCHANGED interval_ctac) end
 
 end
 
@@ -124,6 +138,15 @@ fun CALLGOALS ctac (cst as (_, st)) =
       | doall n = ctac n CTHEN doall (n - 1);
   in doall (Thm.nprems_of st) cst end
 
+fun CSOMEGOAL ctac (cst as (_, st)) =
+  let
+    fun find 0 = no_ctac
+      | find n = ctac n CORELSE find (n - 1);
+  in find (Thm.nprems_of st) cst end
+
+fun CRANGE [] _ = all_ctac
+  | CRANGE (ctac :: ctacs) i = CRANGE ctacs (i + 1) CTHEN ctac i
+
 end
 
 open Context_Tactical
diff --git a/spartan/core/elimination.ML b/spartan/core/elimination.ML
index 11b3af9..cd4e414 100644
--- a/spartan/core/elimination.ML
+++ b/spartan/core/elimination.ML
@@ -34,13 +34,13 @@ fun register_rule tms rl =
   in Rules.map (Termtab.update (hd, (rl, map (#1 o dest_Var) tms))) end
 
 
-(* [elims] attribute *)
+(* [elim] attribute *)
 val _ = Theory.setup (
-  Attrib.setup \<^binding>\<open>elims\<close>
+  Attrib.setup \<^binding>\<open>elim\<close>
     (Scan.repeat Args.term_pattern >>
       (Thm.declaration_attribute o register_rule))
     ""
-  #> Global_Theory.add_thms_dynamic (\<^binding>\<open>elims\<close>,
+  #> Global_Theory.add_thms_dynamic (\<^binding>\<open>elim\<close>,
       fn context => (map #1 (rules (Context.proof_of context))))
 )
 
diff --git a/spartan/core/eqsubst.ML b/spartan/core/eqsubst.ML
index ea6f098..e7ecf63 100644
--- a/spartan/core/eqsubst.ML
+++ b/spartan/core/eqsubst.ML
@@ -416,19 +416,27 @@ fun eqsubst_asm_tac ctxt occs thms i st =
    should be done to an assumption, false = apply to the conclusion of
    the goal) as well as the theorems to use *)
 val _ =
-  Theory.setup
-    (Method.setup \<^binding>\<open>sub\<close>
-      (Scan.lift (Args.mode "asm" -- Scan.optional (Args.parens (Scan.repeat Parse.nat)) [0]) --
-        Attrib.thms >> (fn ((asm, occs), inthms) => fn ctxt =>
-          SIMPLE_METHOD' ((if asm then eqsubst_asm_tac else eqsubst_tac) ctxt occs inthms)))
-      "single-step substitution"
-    #>
-    (Method.setup \<^binding>\<open>subst\<close>
-      (Scan.lift (Args.mode "asm" -- Scan.optional (Args.parens (Scan.repeat Parse.nat)) [0]) --
-        Attrib.thms >> (fn ((asm, occs), inthms) => fn ctxt =>
-          SIMPLE_METHOD' (SIDE_CONDS
-            ((if asm then eqsubst_asm_tac else eqsubst_tac) ctxt occs inthms)
-            ctxt)))
-      "single-step substitution with auto-typechecking"))
+  let
+    val parser =
+      Scan.lift (Args.mode "asm"
+        -- Scan.optional (Args.parens (Scan.repeat Parse.nat)) [0])
+      -- Attrib.thms
+    fun eqsubst_asm_ctac occs inthms =
+      CONTEXT_TACTIC' (fn ctxt => eqsubst_asm_tac ctxt occs inthms)
+    fun eqsubst_ctac occs inthms =
+      CONTEXT_TACTIC' (fn ctxt => eqsubst_tac ctxt occs inthms)
+  in
+    Theory.setup (
+      Method.setup \<^binding>\<open>sub\<close>
+        (parser >> (fn ((asm, occs), inthms) => fn ctxt => SIMPLE_METHOD' (
+          (if asm then eqsubst_asm_tac else eqsubst_tac) ctxt occs inthms)))
+        "single-step substitution" #>
+      Method.setup \<^binding>\<open>subst\<close>
+        (parser >> (fn ((asm, occs), inthms) => K (CONTEXT_METHOD (
+          CHEADGOAL o SIDE_CONDS
+            ((if asm then eqsubst_asm_ctac else eqsubst_ctac) occs inthms)))))
+        "single-step substitution with automatic discharge of side conditions"
+    )
+  end
 
 end;
diff --git a/spartan/core/rewrite.ML b/spartan/core/rewrite.ML
index f9c5d8e..eba0e81 100644
--- a/spartan/core/rewrite.ML
+++ b/spartan/core/rewrite.ML
@@ -15,8 +15,8 @@ patterns but has diverged significantly during its development.
 We also allow introduction of identifiers for bound variables,
 which can then be used to match arbitrary subterms inside abstractions.
 
-This code is slightly modified from the original at HOL/Library/rewrite.ML,
-to incorporate auto-typechecking for type theory.
+This code has been slightly modified from the original at HOL/Library/rewrite.ML
+to incorporate automatic discharge of type-theoretic side conditions.
 *)
 
 infix 1 then_pconv;
@@ -448,18 +448,18 @@ val _ =
     val subst_parser =
       let val scan = raw_pattern -- to_parser -- Parse.thms1
       in context_lift scan prep_args end
+
+    fun rewrite_export_ctac inputs inthms =
+      CONTEXT_TACTIC' (fn ctxt => rewrite_export_tac ctxt inputs inthms)
   in
     Method.setup \<^binding>\<open>rewr\<close> (subst_parser >>
-      (fn (pattern, inthms, (to, pat_ctxt)) => fn orig_ctxt =>
-        SIMPLE_METHOD'
-          (rewrite_export_tac orig_ctxt ((pattern, to), SOME pat_ctxt) inthms)))
-      "single-step rewriting, allowing subterm selection via patterns"
-    #>
-    (Method.setup \<^binding>\<open>rewrite\<close> (subst_parser >>
-      (fn (pattern, inthms, (to, pat_ctxt)) => fn orig_ctxt =>
-        SIMPLE_METHOD' (SIDE_CONDS
-          (rewrite_export_tac orig_ctxt ((pattern, to), SOME pat_ctxt) inthms)
-          orig_ctxt)))
-      "single-step rewriting with auto-typechecking")
+      (fn (pattern, inthms, (to, pat_ctxt)) => fn orig_ctxt => SIMPLE_METHOD'
+        (rewrite_export_tac orig_ctxt ((pattern, to), SOME pat_ctxt) inthms)))
+      "single-step rewriting, allowing subterm selection via patterns" #>
+    Method.setup \<^binding>\<open>rewrite\<close> (subst_parser >>
+      (fn (pattern, inthms, (to, pat_ctxt)) => K (CONTEXT_METHOD (
+        CHEADGOAL o SIDE_CONDS
+          (rewrite_export_ctac ((pattern, to), SOME pat_ctxt) inthms)))))
+      "single-step rewriting with auto-typechecking"
   end
 end
diff --git a/spartan/core/tactics.ML b/spartan/core/tactics.ML
index 172ae90..3922ae0 100644
--- a/spartan/core/tactics.ML
+++ b/spartan/core/tactics.ML
@@ -7,102 +7,66 @@ General tactics for dependent type theory.
 structure Tactics:
 sig
 
-val assumptions_tac: Proof.context -> int -> tactic
-val known_tac: Proof.context -> int -> tactic
-val typechk_tac: Proof.context -> int -> tactic
-val auto_typechk: bool Config.T
-val SIDE_CONDS: (int -> tactic) -> Proof.context -> int -> tactic
-val rule_tac: thm list -> Proof.context -> int -> tactic
-val dest_tac: int option -> thm list -> Proof.context -> int -> tactic
-val intro_tac: Proof.context -> int -> tactic
-val intros_tac: Proof.context -> int -> tactic
-val elim_context_tac: term list -> Proof.context -> int -> context_tactic
-val cases_tac: term -> Proof.context -> int -> tactic
+val solve_side_conds: int Config.T
+val SIDE_CONDS: context_tactic' -> thm list -> context_tactic'
+val rule_ctac: thm list -> context_tactic'
+val dest_ctac: int option -> thm list -> context_tactic'
+val intro_ctac: context_tactic'
+val elim_ctac: term list -> context_tactic'
+val cases_ctac: term -> context_tactic'
 
 end = struct
 
-(*An assumption tactic that only solves typing goals with rigid terms and
-  judgmental equalities without schematic variables*)
-fun assumptions_tac ctxt = SUBGOAL (fn (goal, i) =>
-  let
-    val concl = Logic.strip_assums_concl goal
-  in
-    if
-      Lib.is_typing concl andalso Lib.is_rigid (Lib.term_of_typing concl)
-      orelse not ((exists_subterm is_Var) concl)
-    then assume_tac ctxt i
-    else no_tac
-  end)
-
-(*Solves typing goals with rigid term by resolving with context facts and
-  simplifier premises, or arbitrary goals by *non-unifying* assumption*)
-fun known_tac ctxt = SUBGOAL (fn (goal, i) =>
-  let
-    val concl = Logic.strip_assums_concl goal
-  in
-    ((if Lib.is_typing concl andalso Lib.is_rigid (Lib.term_of_typing concl)
-      then
-        let val ths = map fst (Facts.props (Proof_Context.facts_of ctxt))
-        in resolve_tac ctxt (ths @ Simplifier.prems_of ctxt) end
-      else K no_tac)
-    ORELSE' assumptions_tac ctxt) i
-  end)
-
-(*Typechecking: try to solve goals of the form "a: A" where a is rigid*)
-fun typechk_tac ctxt =
-  let
-    val tac = SUBGOAL (fn (goal, i) =>
-      if Lib.rigid_typing_concl goal
-      then
-        let val net = Tactic.build_net
-          ((Named_Theorems.get ctxt \<^named_theorems>\<open>typechk\<close>)
-          @(Named_Theorems.get ctxt \<^named_theorems>\<open>intros\<close>)
-          @(map #1 (Elim.rules ctxt)))
-        in (resolve_from_net_tac ctxt net) i end
-      else no_tac)
-  in
-    REPEAT_ALL_NEW (known_tac ctxt ORELSE' tac)
-  end
 
-(*Many methods try to automatically discharge side conditions by typechecking.
-  Switch this flag off to discharge by non-unifying assumption instead.*)
-val auto_typechk = Attrib.setup_config_bool \<^binding>\<open>auto_typechk\<close> (K true)
+(* Side conditions *)
+val solve_side_conds =
+  Attrib.setup_config_int \<^binding>\<open>solve_side_conds\<close> (K 2)
+
+fun SIDE_CONDS ctac facts i (cst as (ctxt, st)) = cst |> (ctac i CTHEN
+  (case Config.get ctxt solve_side_conds of
+    1 => CALLGOALS (CTRY o Types.known_ctac facts)
+  | 2 => CREPEAT_IN_RANGE i (Thm.nprems_of st - i)
+      (CTRY o CREPEAT_ALL_NEW_FWD (Types.check_infer facts))
+  | _ => all_ctac))
 
-fun side_cond_tac ctxt = CHANGED o REPEAT o
-  (if Config.get ctxt auto_typechk then typechk_tac ctxt else known_tac ctxt)
 
-(*Combinator runs tactic and tries to discharge all new typing side conditions*)
-fun SIDE_CONDS tac ctxt = tac THEN_ALL_NEW (TRY o side_cond_tac ctxt)
+(* rule, dest, intro *)
 
 local
-fun mk_rules _ ths [] = ths
-  | mk_rules n ths ths' =
-      let val ths'' = foldr1 (op @)
-        (map (fn th => [rotate_prems n (th RS @{thm PiE})] handle THM _ => []) ths')
-      in
-        mk_rules n (ths @ ths') ths''
-      end
+  fun mk_rules _ ths [] = ths
+    | mk_rules n ths ths' =
+        let val ths'' = foldr1 (op @)
+          (map
+            (fn th => [rotate_prems n (th RS @{thm PiE})] handle THM _ => [])
+            ths')
+        in
+          mk_rules n (ths @ ths') ths''
+        end
 in
 
-(*Resolves with given rules, discharging as many side conditions as possible*)
-fun rule_tac ths ctxt = resolve_tac ctxt (mk_rules 0 [] ths)
+(*Resolves with given rules*)
+fun rule_ctac ths i (ctxt, st) =
+  TACTIC_CONTEXT ctxt (resolve_tac ctxt (mk_rules 0 [] ths) i st)
 
 (*Attempts destruct-resolution with the n-th premise of the given rules*)
-fun dest_tac opt_n ths ctxt = dresolve_tac ctxt
-  (mk_rules (case opt_n of NONE => 0 | SOME 0 => 0 | SOME n => n-1) [] ths)
+fun dest_ctac opt_n ths i (ctxt, st) =
+  TACTIC_CONTEXT ctxt (dresolve_tac ctxt
+    (mk_rules (case opt_n of NONE => 0 | SOME 0 => 0 | SOME n => n-1) [] ths)
+    i st)
 
 end
 
 (*Applies some introduction rule*)
-fun intro_tac ctxt = SUBGOAL (fn (_, i) => SIDE_CONDS
-  (resolve_tac ctxt (Named_Theorems.get ctxt \<^named_theorems>\<open>intros\<close>)) ctxt i)
+fun intro_ctac i (ctxt, st) = TACTIC_CONTEXT ctxt (resolve_tac ctxt
+  (Named_Theorems.get ctxt \<^named_theorems>\<open>intros\<close>) i st)
 
-fun intros_tac ctxt = SUBGOAL (fn (_, i) =>
-  (CHANGED o REPEAT o CHANGED o intro_tac ctxt) i)
 
 (* Induction/elimination *)
 
-(*Pushes a context/goal premise typing t:T into a \<Prod>-type*)
+(*Pushes a known typing t:T into a \<Prod>-type.
+  This tactic is well-behaved only when t is sufficiently well specified
+  (otherwise there might be multiple possible judgments t:T that unify, and
+  which is chosen is undefined).*)
 fun internalize_fact_tac t =
   Subgoal.FOCUS_PARAMS (fn {context = ctxt, concl = raw_concl, ...} =>
     let
@@ -116,18 +80,10 @@ fun internalize_fact_tac t =
     in
       HEADGOAL (resolve_tac ctxt [resolvent])
       (*known_tac infers the correct type T inferred by unification*)
-      THEN SOMEGOAL (known_tac ctxt)
+      THEN SOMEGOAL (NO_CONTEXT_TACTIC ctxt o Types.known_ctac [])
     end)
 
-(*Premises that have already been pushed into the \<Prod>-type*)
-structure Inserts = Proof_Data (
-  type T = term Item_Net.T
-  val init = K (Item_Net.init Term.aconv_untyped single)
-)
-
-local
-
-fun elim_core_tac tms types ctxt = SUBGOAL (K (
+fun elim_core_tac tms types ctxt =
   let
     val rule_insts = map ((Elim.lookup_rule ctxt) o Term.head_of) types
     val rules = flat (map
@@ -137,84 +93,86 @@ fun elim_core_tac tms types ctxt = SUBGOAL (K (
           (idxnames ~~ map (Thm.cterm_of ctxt) tms) rl])
       rule_insts)
   in
-    HEADGOAL (resolve_tac ctxt rules)
-    THEN RANGE (replicate (length tms) (typechk_tac ctxt)) 1
-  end handle Option => no_tac))
-
-in
+    resolve_tac ctxt rules
+    THEN' RANGE (replicate (length tms) (NO_CONTEXT_TACTIC ctxt o Types.check_infer []))
+  end handle Option => K no_tac
 
-fun elim_context_tac tms ctxt = case tms of
-    [] => CONTEXT_SUBGOAL (K (Context_Tactic.CONTEXT_TACTIC (HEADGOAL (
-      SIDE_CONDS (eresolve_tac ctxt (map #1 (Elim.rules ctxt))) ctxt))))
-  | major::_  => CONTEXT_SUBGOAL (fn (goal, _) =>
-    let
-      val facts = Proof_Context.facts_of ctxt
-      val prems = Logic.strip_assums_hyp goal
-      val template = Lib.typing_of_term major
-      val types =
-        map (Thm.prop_of o #1) (Facts.could_unify facts template)
-        @ filter (fn prem => Term.could_unify (template, prem)) prems
-        |> map Lib.type_of_typing
-    in case types of
-        [] => Context_Tactic.CONTEXT_TACTIC no_tac
-      | _ =>
-        let
-          val inserts = map (Thm.prop_of o fst) (Facts.props facts) @ prems
-            |> filter Lib.is_typing
-            |> map Lib.dest_typing
-            |> filter_out (fn (t, _) =>
-              Term.aconv (t, major) orelse Item_Net.member (Inserts.get ctxt) t)
-            |> map (fn (t, T) => ((t, T), Lib.subterm_count_distinct tms T))
-            |> filter (fn (_, i) => i > 0)
-            (*`t1: T1` comes before `t2: T2` if T1 contains t2 as subterm.
-              If they are incomparable, then order by decreasing
-              `subterm_count [p, x, y] T`*)
-            |> sort (fn (((t1, _), i), ((_, T2), j)) =>
-                Lib.cond_order (Lib.subterm_order T2 t1) (int_ord (j, i)))
-            |> map (#1 o #1)
-          val record_inserts = Inserts.map (fold Item_Net.update inserts)
-          val tac =
-            (*Push premises having a subterm in `tms` into a \<Prod>*)
-            fold (fn t => fn tac =>
-              tac THEN HEADGOAL (internalize_fact_tac t ctxt))
-              inserts all_tac
-            (*Apply elimination rule*)
-            THEN (HEADGOAL (
-              elim_core_tac tms types ctxt
-              (*Pull pushed premises back out*)
-              THEN_ALL_NEW (SUBGOAL (fn (_, i) =>
-                REPEAT_DETERM_N (length inserts)
-                  (resolve_tac ctxt @{thms PiI} i)))
-            ))
-            (*Side conditions*)
-            THEN ALLGOALS (TRY o side_cond_tac ctxt)
-        in
-          fn (ctxt, st) => Context_Tactic.TACTIC_CONTEXT
-            (record_inserts ctxt) (tac st)
-        end
-    end)
+(*Premises that have already been pushed into the \<Prod>-type*)
+structure Inserts = Proof_Data (
+  type T = term Item_Net.T
+  val init = K (Item_Net.init Term.aconv_untyped single)
+)
 
-fun cases_tac tm ctxt = SUBGOAL (fn (goal, i) =>
-  let
-    val facts = Proof_Context.facts_of ctxt
-    val prems = Logic.strip_assums_hyp goal
-    val template = Lib.typing_of_term tm
-    val types =
-      map (Thm.prop_of o #1) (Facts.could_unify facts template)
-      @ filter (fn prem => Term.could_unify (template, prem)) prems
-      |> map Lib.type_of_typing
-    val res = (case types of
-        [typ] => Drule.infer_instantiate' ctxt [SOME (Thm.cterm_of ctxt tm)]
-          (the (Case.lookup_rule ctxt (Term.head_of typ)))
-      | [] => raise Option
-      | _ => raise error (Syntax.string_of_term ctxt tm ^ "not uniquely typed"))
-      handle Option => error ("no case rule known for "
-        ^ (Syntax.string_of_term ctxt tm))
-  in
-    SIDE_CONDS (resolve_tac ctxt [res]) ctxt i
-  end)
+fun elim_ctac tms =
+  case tms of
+    [] => CONTEXT_TACTIC' (fn ctxt => eresolve_tac ctxt (map #1 (Elim.rules ctxt)))
+  | major :: _ => CONTEXT_SUBGOAL (fn (goal, _) => fn cst as (ctxt, st) =>
+      let
+        val facts = Proof_Context.facts_of ctxt
+        val prems = Logic.strip_assums_hyp goal
+        val template = Lib.typing_of_term major
+        val types =
+          map (Thm.prop_of o #1) (Facts.could_unify facts template)
+          @ filter (fn prem => Term.could_unify (template, prem)) prems
+          |> map Lib.type_of_typing
+      in case types of
+          [] => no_ctac cst
+        | _ =>
+            let
+              val inserts = map (Thm.prop_of o fst) (Facts.props facts) @ prems
+                |> filter Lib.is_typing
+                |> map Lib.dest_typing
+                |> filter_out (fn (t, _) =>
+                  Term.aconv (t, major) orelse Item_Net.member (Inserts.get ctxt) t)
+                |> map (fn (t, T) => ((t, T), Lib.subterm_count_distinct tms T))
+                |> filter (fn (_, i) => i > 0)
+                (*`t1: T1` comes before `t2: T2` if T1 contains t2 as subterm.
+                  If they are incomparable, then order by decreasing
+                  `subterm_count [p, x, y] T`*)
+                |> sort (fn (((t1, _), i), ((_, T2), j)) =>
+                    Lib.cond_order (Lib.subterm_order T2 t1) (int_ord (j, i)))
+                |> map (#1 o #1)
+              val record_inserts = Inserts.map (fold Item_Net.update inserts)
+              val tac =
+                (*Push premises having a subterm in `tms` into a \<Prod>*)
+                fold (fn t => fn tac =>
+                  tac THEN HEADGOAL (internalize_fact_tac t ctxt))
+                  inserts all_tac
+                (*Apply elimination rule*)
+                THEN HEADGOAL (
+                  elim_core_tac tms types ctxt
+                  (*Pull pushed premises back out*)
+                  THEN_ALL_NEW (SUBGOAL (fn (_, i) =>
+                    REPEAT_DETERM_N (length inserts)
+                      (resolve_tac ctxt @{thms PiI[rotated]} i))))
+            in
+              TACTIC_CONTEXT (record_inserts ctxt) (tac st)
+            end
+      end)
+
+fun cases_ctac tm =
+  let fun tac ctxt =
+    SUBGOAL (fn (goal, i) =>
+      let
+        val facts = Proof_Context.facts_of ctxt
+        val prems = Logic.strip_assums_hyp goal
+        val template = Lib.typing_of_term tm
+        val types =
+          map (Thm.prop_of o #1) (Facts.could_unify facts template)
+          @ filter (fn prem => Term.could_unify (template, prem)) prems
+          |> map Lib.type_of_typing
+        val res = (case types of
+            [typ] => Drule.infer_instantiate' ctxt [SOME (Thm.cterm_of ctxt tm)]
+              (the (Case.lookup_rule ctxt (Term.head_of typ)))
+          | [] => raise Option
+          | _ => raise error (Syntax.string_of_term ctxt tm ^ "not uniquely typed"))
+          handle Option =>
+            error ("no case rule known for " ^ (Syntax.string_of_term ctxt tm))
+      in
+        resolve_tac ctxt [res] i
+      end)
+  in CONTEXT_TACTIC' tac end
 
-end
 
 end
 
diff --git a/spartan/core/tactics2.ML b/spartan/core/tactics2.ML
deleted file mode 100644
index 801424f..0000000
--- a/spartan/core/tactics2.ML
+++ /dev/null
@@ -1,191 +0,0 @@
-(*  Title:      tactics.ML
-    Author:     Joshua Chen
-
-General tactics for dependent type theory.
-*)
-
-structure Tactics2:
-sig
-
-val solve_side_conds: bool Config.T
-val SIDE_CONDS: context_tactic' -> thm list -> context_tactic'
-val rule_tac: thm list -> context_tactic'
-val dest_tac: int option -> thm list -> context_tactic'
-val intro_tac: context_tactic'
-val intros_tac: context_tactic'
-(*
-val elim_context_tac: term list -> Proof.context -> int -> context_tactic
-val cases_tac: term -> Proof.context -> int -> tactic
-*)
-
-end = struct
-
-(*Automatically try to solve side conditions?*)
-val solve_side_conds =
-  Attrib.setup_config_bool \<^binding>\<open>solve_side_conds\<close> (K true)
-
-local
-  fun side_cond_ctac facts i (cst as (ctxt, _)) =
-    if Config.get ctxt solve_side_conds
-    then (Types.check_infer facts i) cst
-    else all_ctac cst
-in
-
-(*Combinator runs tactic and tries to discharge newly arising side conditions*)
-fun SIDE_CONDS ctac facts = ctac CTHEN_ALL_NEW (CTRY o side_cond_ctac facts)
-
-end
-
-local
-  fun mk_rules _ ths [] = ths
-    | mk_rules n ths ths' =
-        let val ths'' = foldr1 (op @)
-          (map
-            (fn th => [rotate_prems n (th RS @{thm PiE})] handle THM _ => [])
-            ths')
-        in
-          mk_rules n (ths @ ths') ths''
-        end
-in
-
-(*Resolves with given rules*)
-fun rule_tac ths i (ctxt, st) =
-  TACTIC_CONTEXT ctxt (resolve_tac ctxt (mk_rules 0 [] ths) i st)
-
-(*Attempts destruct-resolution with the n-th premise of the given rules*)
-fun dest_tac opt_n ths i (ctxt, st) =
-  TACTIC_CONTEXT ctxt (dresolve_tac ctxt
-    (mk_rules (case opt_n of NONE => 0 | SOME 0 => 0 | SOME n => n-1) [] ths)
-    i st)
-
-end
-
-(*Applies some introduction rule*)
-fun intro_tac i (ctxt, st) =
-  TACTIC_CONTEXT ctxt (resolve_tac ctxt
-    (Named_Theorems.get ctxt \<^named_theorems>\<open>intros\<close>) i st)
-
-val intros_tac = CONTEXT_SUBGOAL (fn (_, i) =>
-  (CCHANGED o CREPEAT o CCHANGED o intro_tac) i)
-
-(*
-(* Induction/elimination *)
-
-(*Pushes a context/goal premise typing t:T into a \<Prod>-type*)
-fun internalize_fact_tac t =
-  Subgoal.FOCUS_PARAMS (fn {context = ctxt, concl = raw_concl, ...} =>
-    let
-      val concl = Logic.strip_assums_concl (Thm.term_of raw_concl)
-      val C = Lib.type_of_typing concl
-      val B = Thm.cterm_of ctxt (Lib.lambda_var t C)
-      val a = Thm.cterm_of ctxt t
-      (*The resolvent is PiE[where ?B=B and ?a=a]*)
-      val resolvent =
-        Drule.infer_instantiate' ctxt [NONE, NONE, SOME B, SOME a] @{thm PiE}
-    in
-      HEADGOAL (resolve_tac ctxt [resolvent])
-      (*known_tac infers the correct type T inferred by unification*)
-      THEN SOMEGOAL (known_tac ctxt)
-    end)
-
-(*Premises that have already been pushed into the \<Prod>-type*)
-structure Inserts = Proof_Data (
-  type T = term Item_Net.T
-  val init = K (Item_Net.init Term.aconv_untyped single)
-)
-
-local
-
-fun elim_core_tac tms types ctxt = SUBGOAL (K (
-  let
-    val rule_insts = map ((Elim.lookup_rule ctxt) o Term.head_of) types
-    val rules = flat (map
-      (fn rule_inst => case rule_inst of
-          NONE => []
-        | SOME (rl, idxnames) => [Drule.infer_instantiate ctxt
-          (idxnames ~~ map (Thm.cterm_of ctxt) tms) rl])
-      rule_insts)
-  in
-    HEADGOAL (resolve_tac ctxt rules)
-    THEN RANGE (replicate (length tms) (typechk_tac ctxt)) 1
-  end handle Option => no_tac))
-
-in
-
-fun elim_context_tac tms ctxt = case tms of
-    [] => CONTEXT_SUBGOAL (K (Context_Tactic.CONTEXT_TACTIC (HEADGOAL (
-      SIDE_CONDS' (eresolve_tac ctxt (map #1 (Elim.rules ctxt))) ctxt))))
-  | major::_  => CONTEXT_SUBGOAL (fn (goal, _) =>
-    let
-      val facts = Proof_Context.facts_of ctxt
-      val prems = Logic.strip_assums_hyp goal
-      val template = Lib.typing_of_term major
-      val types =
-        map (Thm.prop_of o #1) (Facts.could_unify facts template)
-        @ filter (fn prem => Term.could_unify (template, prem)) prems
-        |> map Lib.type_of_typing
-    in case types of
-        [] => Context_Tactic.CONTEXT_TACTIC no_tac
-      | _ =>
-        let
-          val inserts = map (Thm.prop_of o fst) (Facts.props facts) @ prems
-            |> filter Lib.is_typing
-            |> map Lib.dest_typing
-            |> filter_out (fn (t, _) =>
-              Term.aconv (t, major) orelse Item_Net.member (Inserts.get ctxt) t)
-            |> map (fn (t, T) => ((t, T), Lib.subterm_count_distinct tms T))
-            |> filter (fn (_, i) => i > 0)
-            (*`t1: T1` comes before `t2: T2` if T1 contains t2 as subterm.
-              If they are incomparable, then order by decreasing
-              `subterm_count [p, x, y] T`*)
-            |> sort (fn (((t1, _), i), ((_, T2), j)) =>
-                Lib.cond_order (Lib.subterm_order T2 t1) (int_ord (j, i)))
-            |> map (#1 o #1)
-          val record_inserts = Inserts.map (fold Item_Net.update inserts)
-          val tac =
-            (*Push premises having a subterm in `tms` into a \<Prod>*)
-            fold (fn t => fn tac =>
-              tac THEN HEADGOAL (internalize_fact_tac t ctxt))
-              inserts all_tac
-            (*Apply elimination rule*)
-            THEN (HEADGOAL (
-              elim_core_tac tms types ctxt
-              (*Pull pushed premises back out*)
-              THEN_ALL_NEW (SUBGOAL (fn (_, i) =>
-                REPEAT_DETERM_N (length inserts)
-                  (resolve_tac ctxt @{thms PiI} i)))
-            ))
-            (*Side conditions*)
-            THEN ALLGOALS (TRY o side_cond_tac ctxt)
-        in
-          fn (ctxt, st) => Context_Tactic.TACTIC_CONTEXT
-            (record_inserts ctxt) (tac st)
-        end
-    end)
-
-fun cases_tac tm ctxt = SUBGOAL (fn (goal, i) =>
-  let
-    val facts = Proof_Context.facts_of ctxt
-    val prems = Logic.strip_assums_hyp goal
-    val template = Lib.typing_of_term tm
-    val types =
-      map (Thm.prop_of o #1) (Facts.could_unify facts template)
-      @ filter (fn prem => Term.could_unify (template, prem)) prems
-      |> map Lib.type_of_typing
-    val res = (case types of
-        [typ] => Drule.infer_instantiate' ctxt [SOME (Thm.cterm_of ctxt tm)]
-          (the (Case.lookup_rule ctxt (Term.head_of typ)))
-      | [] => raise Option
-      | _ => raise error (Syntax.string_of_term ctxt tm ^ "not uniquely typed"))
-      handle Option => error ("no case rule known for "
-        ^ (Syntax.string_of_term ctxt tm))
-  in
-    SIDE_CONDS' (resolve_tac ctxt [res]) ctxt i
-  end)
-
-end
-*)
-
-end
-
-open Tactics2
diff --git a/spartan/core/typechecking.ML b/spartan/core/typechecking.ML
index 13ca440..946ecd6 100644
--- a/spartan/core/typechecking.ML
+++ b/spartan/core/typechecking.ML
@@ -35,12 +35,6 @@ fun put_types typings = foldr1 (op o) (map put_type typings)
 
 (* Context tactics for type-checking *)
 
-(*For debugging*)
-structure Probe = Proof_Data (
-  type T = int
-  val init = K 0
-)
-
 (*Solves goals without metavariables and type inference problems by resolving
   with facts or assumption from inline premises.*)
 fun known_ctac facts = CONTEXT_SUBGOAL (fn (goal, i) => fn (ctxt, st) =>
@@ -69,22 +63,23 @@ local
             (*MAYBE FIXME: Remove `typechk` from this list, and instead perform
               definitional unfolding to (w?)hnf.*)
             @(Named_Theorems.get ctxt \<^named_theorems>\<open>typechk\<close>)
-            @(Named_Theorems.get ctxt \<^named_theorems>\<open>intros\<close>)
+            @(Named_Theorems.get ctxt \<^named_theorems>\<open>form\<close>)
+            @(Named_Theorems.get ctxt \<^named_theorems>\<open>intro\<close>)
             @(map #1 (Elim.rules ctxt)))
           in (resolve_from_net_tac ctxt net) i end
         else no_tac)
-      val ctxt' = Probe.map (fn i => i + 1) ctxt
+      val ctxt' = ctxt
     in
       TACTIC_CONTEXT ctxt' (tac i st)
     end
 in
 
-fun check_infer facts =
-  let val probe = K (print_ctac (Int.toString o Probe.get))
+fun check_infer facts i (cst as (_, st)) =
+  let
+    val ctac = known_ctac facts CORELSE' check_infer_step facts
   in
-    CREPEAT_ALL_NEW_FWD (
-      probe CTHEN' known_ctac facts
-      CORELSE' probe CTHEN' check_infer_step facts)
+    cst |> (ctac i CTHEN
+      CREPEAT_IN_RANGE i (Thm.nprems_of st - i) (CTRY o CREPEAT_ALL_NEW_FWD ctac))
   end
 
 end
diff --git a/spartan/lib/List.thy b/spartan/lib/List.thy
index a755859..be86b63 100644
--- a/spartan/lib/List.thy
+++ b/spartan/lib/List.thy
@@ -44,9 +44,10 @@ where
         f x xs (ListInd A (fn xs. C xs) c\<^sub>0 (fn x xs rec. f x xs rec) xs)"
 
 lemmas
-  [intros] = ListF List_nil List_cons and
-  [elims "?xs"] = ListE and
-  [comps] = List_comp_nil List_comp_cons
+  [form] = ListF and
+  [intro, intros] = List_nil List_cons and
+  [elim "?xs"] = ListE and
+  [comp] = List_comp_nil List_comp_cons
 
 abbreviation "ListRec A C \<equiv> ListInd A (fn _. C)"
 
@@ -110,7 +111,7 @@ Lemma head_type [typechk]:
   shows "head xs: Maybe A"
   unfolding head_def by typechk
 
-Lemma head_of_cons [comps]:
+Lemma head_of_cons [comp]:
   assumes "A: U i" "x: A" "xs: List A"
   shows "head (x # xs) \<equiv> some x"
   unfolding head_def by reduce
@@ -120,7 +121,7 @@ Lemma tail_type [typechk]:
   shows "tail xs: List A"
   unfolding tail_def by typechk
 
-Lemma tail_of_cons [comps]:
+Lemma tail_of_cons [comp]:
   assumes "A: U i" "x: A" "xs: List A"
   shows "tail (x # xs) \<equiv> xs"
   unfolding tail_def by reduce
@@ -181,7 +182,7 @@ Lemma rev_type [typechk]:
   shows "rev xs: List A"
   unfolding rev_def by typechk
 
-Lemma rev_nil [comps]:
+Lemma rev_nil [comp]:
   assumes "A: U i"
   shows "rev (nil A) \<equiv> nil A"
   unfolding rev_def by reduce
diff --git a/spartan/lib/Maybe.thy b/spartan/lib/Maybe.thy
index d821920..0ce534c 100644
--- a/spartan/lib/Maybe.thy
+++ b/spartan/lib/Maybe.thy
@@ -54,9 +54,10 @@ Lemma Maybe_comp_some:
   unfolding MaybeInd_def some_def by (reduce add: Maybe_def)
 
 lemmas
-  [intros] = MaybeF Maybe_none Maybe_some and
-  [comps] = Maybe_comp_none Maybe_comp_some and
-  MaybeE [elims "?m"] = MaybeInd[rotated 4]
+  [form] = MaybeF and
+  [intro, intros] = Maybe_none Maybe_some and
+  [comp] = Maybe_comp_none Maybe_comp_some and
+  MaybeE [elim "?m"] = MaybeInd[rotated 4]
 lemmas
   Maybe_cases [cases] = MaybeE
 
diff --git a/spartan/lib/More_Types.thy b/spartan/lib/More_Types.thy
index 0d7096f..55e6554 100644
--- a/spartan/lib/More_Types.thy
+++ b/spartan/lib/More_Types.thy
@@ -16,9 +16,9 @@ notation Sum (infixl "\<or>" 50)
 axiomatization where
   SumF: "\<lbrakk>A: U i; B: U i\<rbrakk> \<Longrightarrow> A \<or> B: U i" and
 
-  Sum_inl: "\<lbrakk>a: A; B: U i\<rbrakk> \<Longrightarrow> inl A B a: A \<or> B" and
+  Sum_inl: "\<lbrakk>B: U i; a: A\<rbrakk> \<Longrightarrow> inl A B a: A \<or> B" and
 
-  Sum_inr: "\<lbrakk>b: B; A: U i\<rbrakk> \<Longrightarrow> inr A B b: A \<or> B" and
+  Sum_inr: "\<lbrakk>A: U i; b: B\<rbrakk> \<Longrightarrow> inr A B b: A \<or> B" and
 
   SumE: "\<lbrakk>
     s: A \<or> B;
@@ -42,9 +42,11 @@ axiomatization where
     \<rbrakk> \<Longrightarrow> SumInd A B (fn s. C s) (fn a. c a) (fn b. d b) (inr A B b) \<equiv> d b"
 
 lemmas
-  [intros] = SumF Sum_inl Sum_inr and
-  [elims ?s] = SumE and
-  [comps] = Sum_comp_inl Sum_comp_inr
+  [form] = SumF and
+  [intro] = Sum_inl Sum_inr and
+  [intros] = Sum_inl[rotated] Sum_inr[rotated] and
+  [elim ?s] = SumE and
+  [comp] = Sum_comp_inl Sum_comp_inr
 
 method left = rule Sum_inl
 method right = rule Sum_inr
@@ -76,10 +78,11 @@ and
   BotE: "\<lbrakk>x: \<bottom>; \<And>x. x: \<bottom> \<Longrightarrow> C x: U i\<rbrakk> \<Longrightarrow> BotInd (fn x. C x) x: C x"
 
 lemmas
-  [intros] = TopF TopI BotF and
-  [elims ?a] = TopE and
-  [elims ?x] = BotE and
-  [comps] = Top_comp
+  [form] = TopF BotF and
+  [intro, intros] = TopI and
+  [elim ?a] = TopE and
+  [elim ?x] = BotE and
+  [comp] = Top_comp
 
 
 section \<open>Booleans\<close>
@@ -125,9 +128,10 @@ Lemma if_false:
   by reduce
 
 lemmas
-  [intros] = BoolF Bool_true Bool_false and
-  [comps] = if_true if_false and
-  [elims ?x] = ifelse
+  [form] = BoolF and
+  [intro, intros] = Bool_true Bool_false and
+  [comp] = if_true if_false and
+  [elim ?x] = ifelse
 lemmas
   BoolE = ifelse
 
@@ -136,7 +140,7 @@ subsection \<open>Notation\<close>
 definition ifelse_i ("if _ then _ else _")
   where [implicit]: "if x then a else b \<equiv> ifelse ? x a b"
 
-no_translations "if x then a else b" \<leftharpoondown> "CONST ifelse C x a b"
+translations "if x then a else b" \<leftharpoondown> "CONST ifelse C x a b"
 
 subsection \<open>Logical connectives\<close>