tuned whitespace;
authorwenzelm
Fri, 13 Dec 2013 13:59:01 +0100
changeset 54736 ba66830fae4c
parent 54734 b91afc3aa3e6
child 54737 6a19eb3bd255
tuned whitespace;
src/HOL/Tools/Function/function_elims.ML
--- a/src/HOL/Tools/Function/function_elims.ML	Fri Dec 13 12:31:45 2013 +0100
+++ b/src/HOL/Tools/Function/function_elims.ML	Fri Dec 13 13:59:01 2013 +0100
@@ -34,117 +34,122 @@
 local
 
 fun propagate_tac i thm =
-  let fun inspect eq = case eq of
-              Const (@{const_name Trueprop}, _) $ (Const (@{const_name HOL.eq}, _) $ Free x $ t) =>
-                  if Logic.occs (Free x, t) then raise Match else true
-            | Const (@{const_name Trueprop}, _) $ (Const (@{const_name HOL.eq}, _) $ t $ Free x) =>
-                  if Logic.occs (Free x, t) then raise Match else false
-            | _ => raise Match;
-      fun mk_eq thm = (if inspect (prop_of thm) then
-                          [thm RS eq_reflection]
-                      else
-                          [Thm.symmetric (thm RS eq_reflection)])
-                      handle Match => [];
-      val ss = Simplifier.global_context (Thm.theory_of_thm thm) empty_ss
-               |> Simplifier.set_mksimps (K mk_eq)
+  let
+    fun inspect eq =
+      (case eq of
+        Const (@{const_name Trueprop}, _) $ (Const (@{const_name HOL.eq}, _) $ Free x $ t) =>
+          if Logic.occs (Free x, t) then raise Match else true
+      | Const (@{const_name Trueprop}, _) $ (Const (@{const_name HOL.eq}, _) $ t $ Free x) =>
+          if Logic.occs (Free x, t) then raise Match else false
+      | _ => raise Match);
+    fun mk_eq thm =
+      (if inspect (prop_of thm) then [thm RS eq_reflection]
+       else [Thm.symmetric (thm RS eq_reflection)])
+      handle Match => [];
+    val ss =
+      Simplifier.global_context (Thm.theory_of_thm thm) empty_ss
+      |> Simplifier.set_mksimps (K mk_eq);
   in
     asm_lr_simp_tac ss i thm
   end;
 
-val eqBoolI = @{lemma "!!P. P ==> P = True" "!!P. ~P ==> P = False" by iprover+}
-val boolE = @{thms HOL.TrueE HOL.FalseE}
-val boolD = @{lemma "!!P. True = P ==> P" "!!P. False = P ==> ~P" by iprover+}
-val eqBool = @{thms HOL.eq_True HOL.eq_False HOL.not_False_eq_True HOL.not_True_eq_False}
+val eqBoolI = @{lemma "!!P. P ==> P = True" "!!P. ~P ==> P = False" by iprover+};
+val boolE = @{thms HOL.TrueE HOL.FalseE};
+val boolD = @{lemma "!!P. True = P ==> P" "!!P. False = P ==> ~P" by iprover+};
+val eqBool = @{thms HOL.eq_True HOL.eq_False HOL.not_False_eq_True HOL.not_True_eq_False};
 
 fun bool_subst_tac ctxt i =
-    REPEAT (EqSubst.eqsubst_asm_tac ctxt [1] eqBool i)
-    THEN REPEAT (dresolve_tac boolD i)
-    THEN REPEAT (eresolve_tac boolE i)
+  REPEAT (EqSubst.eqsubst_asm_tac ctxt [1] eqBool i)
+  THEN REPEAT (dresolve_tac boolD i)
+  THEN REPEAT (eresolve_tac boolE i)
 
 fun mk_bool_elims ctxt elim =
-  let val tac = ALLGOALS (bool_subst_tac ctxt)
-      fun mk_bool_elim b =
-        elim
-        |> Thm.forall_elim b
-        |> Tactic.rule_by_tactic ctxt (TRY (resolve_tac eqBoolI 1))
-        |> Tactic.rule_by_tactic ctxt tac
+  let
+    val tac = ALLGOALS (bool_subst_tac ctxt);
+    fun mk_bool_elim b =
+      elim
+      |> Thm.forall_elim b
+      |> Tactic.rule_by_tactic ctxt (TRY (resolve_tac eqBoolI 1))
+      |> Tactic.rule_by_tactic ctxt tac;
   in
-      map mk_bool_elim [@{cterm True}, @{cterm False}]
+    map mk_bool_elim [@{cterm True}, @{cterm False}]
   end;
 
 in
 
 fun mk_partial_elim_rules ctxt result =
   let
-      val thy = Proof_Context.theory_of ctxt;
+    val thy = Proof_Context.theory_of ctxt;
 
-      val FunctionResult {fs, G, R, dom, psimps, simple_pinducts, cases,
-                          termination, domintros, ...} = result;
-      val n_fs = length fs;
+    val FunctionResult {fs, G, R, dom, psimps, simple_pinducts, cases,
+      termination, domintros, ...} = result;
+    val n_fs = length fs;
 
-      fun mk_partial_elim_rule (idx,f) =
-        let fun mk_funeq 0 T (acc_vars, acc_lhs) =
-                let val y = Free("y",T) in
-                  (y :: acc_vars, (HOLogic.mk_Trueprop (HOLogic.mk_eq (acc_lhs, y))), T)
-                end
-              | mk_funeq n (Type(@{type_name "fun"}, [S, T])) (acc_vars, acc_lhs) =
-                let val xn = Free ("x" ^ Int.toString n,S) in
-                  mk_funeq (n - 1) T (xn :: acc_vars, acc_lhs $ xn)
-                end
-              | mk_funeq _ _ _ = raise (TERM ("Not a function.", [f]))
+    fun mk_partial_elim_rule (idx, f) =
+      let
+        fun mk_funeq 0 T (acc_vars, acc_lhs) =
+              let val y = Free("y", T)
+              in (y :: acc_vars, (HOLogic.mk_Trueprop (HOLogic.mk_eq (acc_lhs, y))), T) end
+          | mk_funeq n (Type (@{type_name "fun"}, [S, T])) (acc_vars, acc_lhs) =
+              let val xn = Free ("x" ^ Int.toString n, S)
+              in mk_funeq (n - 1) T (xn :: acc_vars, acc_lhs $ xn) end
+          | mk_funeq _ _ _ = raise (TERM ("Not a function.", [f]));
 
-            val f_simps = filter (fn r => (prop_of r |> Logic.strip_assums_concl
-                                           |> HOLogic.dest_Trueprop
-                                           |> dest_funprop |> fst |> fst) = f)
-                                 psimps
+        val f_simps =
+          filter (fn r =>
+            (prop_of r |> Logic.strip_assums_concl
+              |> HOLogic.dest_Trueprop
+              |> dest_funprop |> fst |> fst) = f)
+            psimps;
 
-            val arity = hd f_simps |> prop_of |> Logic.strip_assums_concl
-                                   |> HOLogic.dest_Trueprop
-                                   |> snd o fst o dest_funprop |> length;
-            val (free_vars,prop,ranT) = mk_funeq arity (fastype_of f) ([],f)
-            val (rhs_var, arg_vars) = case free_vars of x::xs => (x, rev xs)
-            val args = HOLogic.mk_tuple arg_vars;
-            val domT = R |> dest_Free |> snd |> hd o snd o dest_Type
-
-            val sumtree_inj = SumTree.mk_inj domT n_fs (idx+1) args;
-
-            val cprop = cterm_of thy prop
+        val arity =
+          hd f_simps
+          |> prop_of
+          |> Logic.strip_assums_concl
+          |> HOLogic.dest_Trueprop
+          |> snd o fst o dest_funprop
+          |> length;
+        val (free_vars,prop,ranT) = mk_funeq arity (fastype_of f) ([], f);
+        val (rhs_var, arg_vars) = (case free_vars of x :: xs => (x, rev xs));
+        val args = HOLogic.mk_tuple arg_vars;
+        val domT = R |> dest_Free |> snd |> hd o snd o dest_Type;
 
-            val asms = [cprop, cterm_of thy (HOLogic.mk_Trueprop (dom $ sumtree_inj))];
-            val asms_thms = map Thm.assume asms;
+        val sumtree_inj = SumTree.mk_inj domT n_fs (idx+1) args;
+
+        val cprop = cterm_of thy prop;
+
+        val asms = [cprop, cterm_of thy (HOLogic.mk_Trueprop (dom $ sumtree_inj))];
+        val asms_thms = map Thm.assume asms;
 
-            fun prep_subgoal i =
-              REPEAT (eresolve_tac @{thms Pair_inject} i)
-              THEN Method.insert_tac (case asms_thms of
-                                        thm::thms => (thm RS sym) :: thms) i
-              THEN propagate_tac i
-              THEN TRY
-                  ((EqSubst.eqsubst_asm_tac ctxt [1] psimps i) THEN atac i)
-              THEN bool_subst_tac ctxt i;
+        fun prep_subgoal i =
+          REPEAT (eresolve_tac @{thms Pair_inject} i)
+          THEN Method.insert_tac (case asms_thms of thm :: thms => (thm RS sym) :: thms) i
+          THEN propagate_tac i
+          THEN TRY ((EqSubst.eqsubst_asm_tac ctxt [1] psimps i) THEN atac i)
+          THEN bool_subst_tac ctxt i;
 
-          val tac = ALLGOALS prep_subgoal;
+      val tac = ALLGOALS prep_subgoal;
 
-          val elim_stripped =
-                nth cases idx
-                |> Thm.forall_elim @{cterm "P::bool"}
-                |> Thm.forall_elim (cterm_of thy args)
-                |> Tactic.rule_by_tactic ctxt tac
-                |> fold_rev Thm.implies_intr asms
-                |> Thm.forall_intr (cterm_of thy rhs_var)
+      val elim_stripped =
+        nth cases idx
+        |> Thm.forall_elim @{cterm "P::bool"}
+        |> Thm.forall_elim (cterm_of thy args)
+        |> Tactic.rule_by_tactic ctxt tac
+        |> fold_rev Thm.implies_intr asms
+        |> Thm.forall_intr (cterm_of thy rhs_var);
 
-          val bool_elims = (case ranT of
-                              Type (@{type_name bool}, []) => mk_bool_elims ctxt elim_stripped
-                              | _ => []);
+      val bool_elims =
+        (case ranT of
+          Type (@{type_name bool}, []) => mk_bool_elims ctxt elim_stripped
+        | _ => []);
 
-          fun unstrip rl =
-                rl  |> (fn thm => List.foldr (uncurry Thm.forall_intr) thm
-                           (map (cterm_of thy) arg_vars))
-                    |> Thm.forall_intr @{cterm "P::bool"}
-
-      in
-        map unstrip (elim_stripped :: bool_elims)
-      end;
-
+      fun unstrip rl =
+        rl
+        |> (fn thm => List.foldr (uncurry Thm.forall_intr) thm (map (cterm_of thy) arg_vars))
+        |> Thm.forall_intr @{cterm "P::bool"};
+    in
+      map unstrip (elim_stripped :: bool_elims)
+    end;
   in
     map_index mk_partial_elim_rule fs
   end;