src/HOL/Tools/simpdata.ML
changeset 28952 15a4b2cf8c34
parent 28262 aa7ca36d67fd
child 30190 479806475f3c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/Tools/simpdata.ML	Wed Dec 03 15:58:44 2008 +0100
@@ -0,0 +1,200 @@
+(*  Title:      HOL/simpdata.ML
+    ID:         $Id$
+    Author:     Tobias Nipkow
+    Copyright   1991  University of Cambridge
+
+Instantiation of the generic simplifier for HOL.
+*)
+
+(** tools setup **)
+
+structure Quantifier1 = Quantifier1Fun
+(struct
+  (*abstract syntax*)
+  fun dest_eq ((c as Const("op =",_)) $ s $ t) = SOME (c, s, t)
+    | dest_eq _ = NONE;
+  fun dest_conj ((c as Const("op &",_)) $ s $ t) = SOME (c, s, t)
+    | dest_conj _ = NONE;
+  fun dest_imp ((c as Const("op -->",_)) $ s $ t) = SOME (c, s, t)
+    | dest_imp _ = NONE;
+  val conj = HOLogic.conj
+  val imp  = HOLogic.imp
+  (*rules*)
+  val iff_reflection = @{thm eq_reflection}
+  val iffI = @{thm iffI}
+  val iff_trans = @{thm trans}
+  val conjI= @{thm conjI}
+  val conjE= @{thm conjE}
+  val impI = @{thm impI}
+  val mp   = @{thm mp}
+  val uncurry = @{thm uncurry}
+  val exI  = @{thm exI}
+  val exE  = @{thm exE}
+  val iff_allI = @{thm iff_allI}
+  val iff_exI = @{thm iff_exI}
+  val all_comm = @{thm all_comm}
+  val ex_comm = @{thm ex_comm}
+end);
+
+structure Simpdata =
+struct
+
+fun mk_meta_eq r = r RS @{thm eq_reflection};
+fun safe_mk_meta_eq r = mk_meta_eq r handle Thm.THM _ => r;
+
+fun mk_eq th = case concl_of th
+  (*expects Trueprop if not == *)
+  of Const ("==",_) $ _ $ _ => th
+   | _ $ (Const ("op =", _) $ _ $ _) => mk_meta_eq th
+   | _ $ (Const ("Not", _) $ _) => th RS @{thm Eq_FalseI}
+   | _ => th RS @{thm Eq_TrueI}
+
+fun mk_eq_True r =
+  SOME (r RS @{thm meta_eq_to_obj_eq} RS @{thm Eq_TrueI}) handle Thm.THM _ => NONE;
+
+(* Produce theorems of the form
+  (P1 =simp=> ... =simp=> Pn => x == y) ==> (P1 =simp=> ... =simp=> Pn => x = y)
+*)
+
+fun lift_meta_eq_to_obj_eq i st =
+  let
+    fun count_imp (Const ("HOL.simp_implies", _) $ P $ Q) = 1 + count_imp Q
+      | count_imp _ = 0;
+    val j = count_imp (Logic.strip_assums_concl (List.nth (prems_of st, i - 1)))
+  in if j = 0 then @{thm meta_eq_to_obj_eq}
+    else
+      let
+        val Ps = map (fn k => Free ("P" ^ string_of_int k, propT)) (1 upto j);
+        fun mk_simp_implies Q = foldr (fn (R, S) =>
+          Const ("HOL.simp_implies", propT --> propT --> propT) $ R $ S) Q Ps
+        val aT = TFree ("'a", HOLogic.typeS);
+        val x = Free ("x", aT);
+        val y = Free ("y", aT)
+      in Goal.prove_global (Thm.theory_of_thm st) []
+        [mk_simp_implies (Logic.mk_equals (x, y))]
+        (mk_simp_implies (HOLogic.mk_Trueprop (HOLogic.mk_eq (x, y))))
+        (fn {prems, ...} => EVERY
+         [rewrite_goals_tac @{thms simp_implies_def},
+          REPEAT (ares_tac (@{thm meta_eq_to_obj_eq} ::
+            map (rewrite_rule @{thms simp_implies_def}) prems) 1)])
+      end
+  end;
+
+(*Congruence rules for = (instead of ==)*)
+fun mk_meta_cong rl = zero_var_indexes
+  (let val rl' = Seq.hd (TRYALL (fn i => fn st =>
+     rtac (lift_meta_eq_to_obj_eq i st) i st) rl)
+   in mk_meta_eq rl' handle THM _ =>
+     if can Logic.dest_equals (concl_of rl') then rl'
+     else error "Conclusion of congruence rules must be =-equality"
+   end);
+
+fun mk_atomize pairs =
+  let
+    fun atoms thm =
+      let
+        fun res th = map (fn rl => th RS rl);   (*exception THM*)
+        fun res_fixed rls =
+          if Thm.maxidx_of (Thm.adjust_maxidx_thm ~1 thm) = ~1 then res thm rls
+          else Variable.trade (K (fn [thm'] => res thm' rls)) (Variable.thm_context thm) [thm];
+      in
+        case concl_of thm
+          of Const ("Trueprop", _) $ p => (case head_of p
+            of Const (a, _) => (case AList.lookup (op =) pairs a
+              of SOME rls => (maps atoms (res_fixed rls) handle THM _ => [thm])
+              | NONE => [thm])
+            | _ => [thm])
+          | _ => [thm]
+      end;
+  in atoms end;
+
+fun mksimps pairs =
+  map_filter (try mk_eq) o mk_atomize pairs o gen_all;
+
+fun unsafe_solver_tac prems =
+  (fn i => REPEAT_DETERM (match_tac @{thms simp_impliesI} i)) THEN'
+  FIRST' [resolve_tac (reflexive_thm :: @{thm TrueI} :: @{thm refl} :: prems), atac,
+    etac @{thm FalseE}];
+
+val unsafe_solver = mk_solver "HOL unsafe" unsafe_solver_tac;
+
+
+(*No premature instantiation of variables during simplification*)
+fun safe_solver_tac prems =
+  (fn i => REPEAT_DETERM (match_tac @{thms simp_impliesI} i)) THEN'
+  FIRST' [match_tac (reflexive_thm :: @{thm TrueI} :: @{thm refl} :: prems),
+         eq_assume_tac, ematch_tac @{thms FalseE}];
+
+val safe_solver = mk_solver "HOL safe" safe_solver_tac;
+
+structure SplitterData =
+struct
+  structure Simplifier = Simplifier
+  val mk_eq           = mk_eq
+  val meta_eq_to_iff  = @{thm meta_eq_to_obj_eq}
+  val iffD            = @{thm iffD2}
+  val disjE           = @{thm disjE}
+  val conjE           = @{thm conjE}
+  val exE             = @{thm exE}
+  val contrapos       = @{thm contrapos_nn}
+  val contrapos2      = @{thm contrapos_pp}
+  val notnotD         = @{thm notnotD}
+end;
+
+structure Splitter = SplitterFun(SplitterData);
+
+val split_tac        = Splitter.split_tac;
+val split_inside_tac = Splitter.split_inside_tac;
+
+val op addsplits     = Splitter.addsplits;
+val op delsplits     = Splitter.delsplits;
+val Addsplits        = Splitter.Addsplits;
+val Delsplits        = Splitter.Delsplits;
+
+
+(* integration of simplifier with classical reasoner *)
+
+structure Clasimp = ClasimpFun
+ (structure Simplifier = Simplifier and Splitter = Splitter
+  and Classical  = Classical and Blast = Blast
+  val iffD1 = @{thm iffD1} val iffD2 = @{thm iffD2} val notE = @{thm notE});
+open Clasimp;
+
+val _ = ML_Antiquote.value "clasimpset"
+  (Scan.succeed "Clasimp.local_clasimpset_of (ML_Context.the_local_context ())");
+
+val mksimps_pairs =
+  [("op -->", [@{thm mp}]), ("op &", [@{thm conjunct1}, @{thm conjunct2}]),
+   ("All", [@{thm spec}]), ("True", []), ("False", []),
+   ("HOL.If", [@{thm if_bool_eq_conj} RS @{thm iffD1}])];
+
+val HOL_basic_ss =
+  Simplifier.theory_context (the_context ()) empty_ss
+    setsubgoaler asm_simp_tac
+    setSSolver safe_solver
+    setSolver unsafe_solver
+    setmksimps (mksimps mksimps_pairs)
+    setmkeqTrue mk_eq_True
+    setmkcong mk_meta_cong;
+
+fun hol_simplify rews = Simplifier.full_simplify (HOL_basic_ss addsimps rews);
+
+fun unfold_tac ths =
+  let val ss0 = Simplifier.clear_ss HOL_basic_ss addsimps ths
+  in fn ss => ALLGOALS (full_simp_tac (Simplifier.inherit_context ss ss0)) end;
+
+val defALL_regroup =
+  Simplifier.simproc (the_context ())
+    "defined ALL" ["ALL x. P x"] Quantifier1.rearrange_all;
+
+val defEX_regroup =
+  Simplifier.simproc (the_context ())
+    "defined EX" ["EX x. P x"] Quantifier1.rearrange_ex;
+
+
+val simpset_simprocs = HOL_basic_ss addsimprocs [defALL_regroup, defEX_regroup]
+
+end;
+
+structure Splitter = Simpdata.Splitter;
+structure Clasimp = Simpdata.Clasimp;