cong setup now part of Simplifier;
authorwenzelm
Tue, 29 Aug 2000 00:55:31 +0200
changeset 9713 2c5b42311eb0
parent 9712 e33422a2eb9c
child 9714 79db0e5b7824
cong setup now part of Simplifier;
src/FOL/FOL.thy
src/FOL/simpdata.ML
src/HOL/HOL.thy
src/HOL/simpdata.ML
src/Sequents/simpdata.ML
--- a/src/FOL/FOL.thy	Tue Aug 29 00:54:22 2000 +0200
+++ b/src/FOL/FOL.thy	Tue Aug 29 00:55:31 2000 +0200
@@ -55,7 +55,6 @@
 
 use "simpdata.ML"
 setup simpsetup
-setup cong_attrib_setup
 setup "Simplifier.method_setup Splitter.split_modifiers"
 setup Splitter.setup
 setup Clasimp.setup
--- a/src/FOL/simpdata.ML	Tue Aug 29 00:54:22 2000 +0200
+++ b/src/FOL/simpdata.ML	Tue Aug 29 00:55:31 2000 +0200
@@ -6,7 +6,7 @@
 Simplification data for FOL
 *)
 
-(*** Addition of rules to simpsets and clasets simultaneously ***)	(* FIXME move to Provers/clasimp.ML? *)
+(*** Addition of rules to simpsets and clasets simultaneously ***)      (* FIXME move to Provers/clasimp.ML? *)
 
 infix 4 addIffs delIffs;
 
@@ -30,15 +30,15 @@
 
   fun delIff ((cla, simp), th) = 
       (case FOLogic.dest_Trueprop (#prop (rep_thm th)) of
-	   (Const ("Not", _) $ A) =>
-	       cla delrules [zero_var_indexes (th RS notE)]
-	 | (Const("op <->", _) $ _ $ _) =>
-	       cla delrules [zero_var_indexes (th RS iffD2),
-			     cla_make_elim (zero_var_indexes (th RS iffD1))]
-	 | _ => cla delrules [th],
+           (Const ("Not", _) $ A) =>
+               cla delrules [zero_var_indexes (th RS notE)]
+         | (Const("op <->", _) $ _ $ _) =>
+               cla delrules [zero_var_indexes (th RS iffD2),
+                             cla_make_elim (zero_var_indexes (th RS iffD1))]
+         | _ => cla delrules [th],
        simp delsimps [th])
       handle TERM _ => (warning("DelIffs: ignoring conditional theorem\n" ^ 
-				string_of_thm th); (cla, simp));
+                                string_of_thm th); (cla, simp));
 
   fun store_clasimp (cla, simp) = (claset_ref () := cla; simpset_ref () := simp)
 in
@@ -139,6 +139,7 @@
     rule_by_tactic 
       (REPEAT_FIRST (resolve_tac [meta_eq_to_obj_eq, def_imp_iff]));
 
+(*Congruence rules for = or <-> (instead of ==)*)
 fun mk_meta_cong rl =
   standard(mk_meta_eq (mk_meta_prems rl))
   handle THM _ =>
@@ -188,29 +189,29 @@
 
 (*existential miniscoping*)
 val int_ex_simps = map int_prove_fun 
-		     ["(EX x. P(x) & Q) <-> (EX x. P(x)) & Q",
-		      "(EX x. P & Q(x)) <-> P & (EX x. Q(x))",
-		      "(EX x. P(x) | Q) <-> (EX x. P(x)) | Q",
-		      "(EX x. P | Q(x)) <-> P | (EX x. Q(x))"];
+                     ["(EX x. P(x) & Q) <-> (EX x. P(x)) & Q",
+                      "(EX x. P & Q(x)) <-> P & (EX x. Q(x))",
+                      "(EX x. P(x) | Q) <-> (EX x. P(x)) | Q",
+                      "(EX x. P | Q(x)) <-> P | (EX x. Q(x))"];
 
 (*classical rules*)
 val cla_ex_simps = map prove_fun 
                      ["(EX x. P(x) --> Q) <-> (ALL x. P(x)) --> Q",
-		      "(EX x. P --> Q(x)) <-> P --> (EX x. Q(x))"];
+                      "(EX x. P --> Q(x)) <-> P --> (EX x. Q(x))"];
 
 val ex_simps = int_ex_simps @ cla_ex_simps;
 
 (*universal miniscoping*)
 val int_all_simps = map int_prove_fun
-		      ["(ALL x. P(x) & Q) <-> (ALL x. P(x)) & Q",
-		       "(ALL x. P & Q(x)) <-> P & (ALL x. Q(x))",
-		       "(ALL x. P(x) --> Q) <-> (EX x. P(x)) --> Q",
-		       "(ALL x. P --> Q(x)) <-> P --> (ALL x. Q(x))"];
+                      ["(ALL x. P(x) & Q) <-> (ALL x. P(x)) & Q",
+                       "(ALL x. P & Q(x)) <-> P & (ALL x. Q(x))",
+                       "(ALL x. P(x) --> Q) <-> (EX x. P(x)) --> Q",
+                       "(ALL x. P --> Q(x)) <-> P --> (ALL x. Q(x))"];
 
 (*classical rules*)
 val cla_all_simps = map prove_fun
                       ["(ALL x. P(x) | Q) <-> (ALL x. P(x)) | Q",
-		       "(ALL x. P | Q(x)) <-> P | (ALL x. Q(x))"];
+                       "(ALL x. P | Q(x)) <-> P | (ALL x. Q(x))"];
 
 val all_simps = int_all_simps @ cla_all_simps;
 
@@ -338,28 +339,6 @@
 open Induction;
 
 
-(* Add congruence rules for = or <-> (instead of ==) *)
-
-(* ###FIXME: Move to simplifier, 
-   taking mk_meta_cong as input, eliminating addeqcongs and deleqcongs *)
-infix 4 addcongs delcongs;
-fun ss addcongs congs = ss addeqcongs (map mk_meta_cong congs);
-fun ss delcongs congs = ss deleqcongs (map mk_meta_cong congs);
-fun Addcongs congs = (simpset_ref() := simpset() addcongs congs);
-fun Delcongs congs = (simpset_ref() := simpset() delcongs congs);
-
-val cong_add_global = Simplifier.change_global_ss (op addcongs);
-val cong_del_global = Simplifier.change_global_ss (op delcongs);
-val cong_add_local = Simplifier.change_local_ss (op addcongs);
-val cong_del_local = Simplifier.change_local_ss (op delcongs);
-
-val cong_attrib_setup =
- [Attrib.add_attributes [("cong",
-   (Attrib.add_del_args cong_add_global cong_del_global,
-    Attrib.add_del_args cong_add_local cong_del_local),
-    "declare Simplifier congruence rules")]];
-
-
 val meta_simps =
    [triv_forall_equality,  (* prunes params *)
     True_implies_equals];  (* prune asms `True' *)
@@ -372,27 +351,28 @@
 val triv_rls = [TrueI,refl,reflexive_thm,iff_refl,notFalseI];
 
 fun unsafe_solver prems = FIRST'[resolve_tac (triv_rls@prems),
-				 atac, etac FalseE];
+                                 atac, etac FalseE];
 (*No premature instantiation of variables during simplification*)
 fun   safe_solver prems = FIRST'[match_tac (triv_rls@prems),
-				 eq_assume_tac, ematch_tac [FalseE]];
+                                 eq_assume_tac, ematch_tac [FalseE]];
 
 (*No simprules, but basic infastructure for simplification*)
-val FOL_basic_ss = empty_ss setsubgoaler asm_simp_tac
-                            addsimprocs [defALL_regroup,defEX_regroup]
-			    setSSolver  (mk_solver "FOL safe" safe_solver)
-			    setSolver  (mk_solver "FOL unsafe" unsafe_solver)
-			    setmksimps (mksimps mksimps_pairs);
-
+val FOL_basic_ss =
+  empty_ss setsubgoaler asm_simp_tac
+    addsimprocs [defALL_regroup, defEX_regroup]
+    setSSolver (mk_solver "FOL safe" safe_solver)
+    setSolver (mk_solver "FOL unsafe" unsafe_solver)
+    setmksimps (mksimps mksimps_pairs)
+    setmkcong mk_meta_cong;
 
 
 (*intuitionistic simprules only*)
-val IFOL_ss = 
-    FOL_basic_ss addsimps (meta_simps @ IFOL_simps @ 
-			   int_ex_simps @ int_all_simps)
+val IFOL_ss =
+    FOL_basic_ss addsimps (meta_simps @ IFOL_simps @
+                           int_ex_simps @ int_all_simps)
                  addcongs [imp_cong];
 
-val cla_simps = 
+val cla_simps =
     [de_Morgan_conj, de_Morgan_disj, imp_disj1, imp_disj2,
      not_all, not_ex, cases_simp] @
     map prove_fun
--- a/src/HOL/HOL.thy	Tue Aug 29 00:54:22 2000 +0200
+++ b/src/HOL/HOL.thy	Tue Aug 29 00:55:31 2000 +0200
@@ -217,8 +217,7 @@
 
 use "blastdata.ML"	setup Blast.setup
 use "simpdata.ML"	setup Simplifier.setup
-			setup "Simplifier.method_setup Splitter.split_modifiers"
-			setup simpsetup setup cong_attrib_setup
+			setup "Simplifier.method_setup Splitter.split_modifiers" setup simpsetup
                         setup Splitter.setup setup Clasimp.setup setup iff_attrib_setup
 
 
--- a/src/HOL/simpdata.ML	Tue Aug 29 00:54:22 2000 +0200
+++ b/src/HOL/simpdata.ML	Tue Aug 29 00:55:31 2000 +0200
@@ -8,46 +8,46 @@
 
 section "Simplifier";
 
-(*** Addition of rules to simpsets and clasets simultaneously ***)	(* FIXME move to Provers/clasimp.ML? *)
+(*** Addition of rules to simpsets and clasets simultaneously ***)      (* FIXME move to Provers/clasimp.ML? *)
 
 infix 4 addIffs delIffs;
 
-(*Takes UNCONDITIONAL theorems of the form A<->B to 
-        the Safe Intr     rule B==>A and 
+(*Takes UNCONDITIONAL theorems of the form A<->B to
+        the Safe Intr     rule B==>A and
         the Safe Destruct rule A==>B.
   Also ~A goes to the Safe Elim rule A ==> ?R
   Failing other cases, A is added as a Safe Intr rule*)
 local
   val iff_const = HOLogic.eq_const HOLogic.boolT;
 
-  fun addIff ((cla, simp), th) = 
+  fun addIff ((cla, simp), th) =
       (case HOLogic.dest_Trueprop (#prop (rep_thm th)) of
                 (Const("Not", _) $ A) =>
                     cla addSEs [zero_var_indexes (th RS notE)]
               | (con $ _ $ _) =>
                     if con = iff_const
-                    then cla addSIs [zero_var_indexes (th RS iffD2)]  
+                    then cla addSIs [zero_var_indexes (th RS iffD2)]
                               addSDs [zero_var_indexes (th RS iffD1)]
                     else  cla addSIs [th]
               | _ => cla addSIs [th],
        simp addsimps [th])
-      handle TERM _ => error ("AddIffs: theorem must be unconditional\n" ^ 
+      handle TERM _ => error ("AddIffs: theorem must be unconditional\n" ^
                          string_of_thm th);
 
-  fun delIff ((cla, simp), th) = 
+  fun delIff ((cla, simp), th) =
       (case HOLogic.dest_Trueprop (#prop (rep_thm th)) of
-	   (Const ("Not", _) $ A) =>
-	       cla delrules [zero_var_indexes (th RS notE)]
-	 | (con $ _ $ _) =>
-	       if con = iff_const
-	       then cla delrules 
-		        [zero_var_indexes (th RS iffD2),
-			 cla_make_elim (zero_var_indexes (th RS iffD1))]
-	       else cla delrules [th]
-	 | _ => cla delrules [th],
+           (Const ("Not", _) $ A) =>
+               cla delrules [zero_var_indexes (th RS notE)]
+         | (con $ _ $ _) =>
+               if con = iff_const
+               then cla delrules
+                        [zero_var_indexes (th RS iffD2),
+                         cla_make_elim (zero_var_indexes (th RS iffD1))]
+               else cla delrules [th]
+         | _ => cla delrules [th],
        simp delsimps [th])
-      handle TERM _ => (warning("DelIffs: ignoring conditional theorem\n" ^ 
-				string_of_thm th); (cla, simp));
+      handle TERM _ => (warning("DelIffs: ignoring conditional theorem\n" ^
+                                string_of_thm th); (cla, simp));
 
   fun store_clasimp (cla, simp) = (claset_ref () := cla; simpset_ref () := simp)
 in
@@ -89,6 +89,7 @@
 
 fun mk_eq_True r = Some(r RS meta_eq_to_obj_eq RS Eq_TrueI);
 
+(*Congruence rules for = (instead of ==)*)
 fun mk_meta_cong rl =
   standard(mk_meta_eq(replicate (nprems_of rl) meta_eq_to_obj_eq MRS rl))
   handle THM _ =>
@@ -101,45 +102,23 @@
    "(~True) = False", "(~False) = True",
    "(~P) ~= P", "P ~= (~P)", "(P ~= Q) = (P = (~Q))",
    "(True=P) = P", "(P=True) = P", "(False=P) = (~P)", "(P=False) = (~P)",
-   "(True --> P) = P", "(False --> P) = True", 
+   "(True --> P) = P", "(False --> P) = True",
    "(P --> True) = True", "(P --> P) = True",
    "(P --> False) = (~P)", "(P --> ~P) = (~P)",
-   "(P & True) = P", "(True & P) = P", 
+   "(P & True) = P", "(True & P) = P",
    "(P & False) = False", "(False & P) = False",
    "(P & P) = P", "(P & (P & Q)) = (P & Q)",
    "(P & ~P) = False",    "(~P & P) = False",
-   "(P | True) = True", "(True | P) = True", 
+   "(P | True) = True", "(True | P) = True",
    "(P | False) = P", "(False | P) = P",
    "(P | P) = P", "(P | (P | Q)) = (P | Q)",
    "(P | ~P) = True",    "(~P | P) = True",
    "((~P) = (~Q)) = (P=Q)",
-   "(!x. P) = P", "(? x. P) = P", "? x. x=t", "? x. t=x", 
+   "(!x. P) = P", "(? x. P) = P", "? x. x=t", "? x. t=x",
 (*two needed for the one-point-rule quantifier simplification procs*)
-   "(? x. x=t & P(x)) = P(t)",		(*essential for termination!!*)
+   "(? x. x=t & P(x)) = P(t)",          (*essential for termination!!*)
    "(! x. t=x --> P(x)) = P(t)" ];      (*covers a stray case*)
 
-(* Add congruence rules for = (instead of ==) *)
-
-(* ###FIXME: Move to simplifier, 
-   taking mk_meta_cong as input, eliminating addeqcongs and deleqcongs *)
-infix 4 addcongs delcongs;
-fun ss addcongs congs = ss addeqcongs (map mk_meta_cong congs);
-fun ss delcongs congs = ss deleqcongs (map mk_meta_cong congs);
-fun Addcongs congs = (simpset_ref() := simpset() addcongs congs);
-fun Delcongs congs = (simpset_ref() := simpset() delcongs congs);
-
-val cong_add_global = Simplifier.change_global_ss (op addcongs);
-val cong_del_global = Simplifier.change_global_ss (op delcongs);
-val cong_add_local = Simplifier.change_local_ss (op addcongs);
-val cong_del_local = Simplifier.change_local_ss (op delcongs);
-
-val cong_attrib_setup =
- [Attrib.add_attributes [("cong",
-   (Attrib.add_del_args cong_add_global cong_del_global,
-    Attrib.add_del_args cong_add_local cong_del_local),
-    "declare Simplifier congruence rules")]];
-
-
 val imp_cong = impI RSN
     (2, prove_goal (the_context ()) "(P=P')--> (P'--> (Q=Q'))--> ((P-->Q) = (P'-->Q'))"
         (fn _=> [(Blast_tac 1)]) RS mp RS mp);
@@ -235,8 +214,8 @@
 prove "iff_conv_conj_imp" "(P = Q) = ((P --> Q) & (Q --> P))";
 
 
-(*Avoids duplication of subgoals after split_if, when the true and false 
-  cases boil down to the same thing.*) 
+(*Avoids duplication of subgoals after split_if, when the true and false
+  cases boil down to the same thing.*)
 prove "cases_simp" "((P --> Q) & (~P --> Q)) = Q";
 
 prove "not_all" "(~ (! x. P(x))) = (? x.~P(x))";
@@ -250,19 +229,19 @@
 (* '&' congruence rule: not included by default!
    May slow rewrite proofs down by as much as 50% *)
 
-let val th = prove_goal (the_context ()) 
+let val th = prove_goal (the_context ())
                 "(P=P')--> (P'--> (Q=Q'))--> ((P&Q) = (P'&Q'))"
                 (fn _=> [(Blast_tac 1)])
 in  bind_thm("conj_cong",standard (impI RSN (2, th RS mp RS mp)))  end;
 
-let val th = prove_goal (the_context ()) 
+let val th = prove_goal (the_context ())
                 "(Q=Q')--> (Q'--> (P=P'))--> ((P&Q) = (P'&Q'))"
                 (fn _=> [(Blast_tac 1)])
 in  bind_thm("rev_conj_cong",standard (impI RSN (2, th RS mp RS mp)))  end;
 
 (* '|' congruence rule: not included by default! *)
 
-let val th = prove_goal (the_context ()) 
+let val th = prove_goal (the_context ())
                 "(P=P')--> (~P'--> (Q=Q'))--> ((P|Q) = (P'|Q'))"
                 (fn _=> [(Blast_tac 1)])
 in  bind_thm("disj_cong",standard (impI RSN (2, th RS mp RS mp)))  end;
@@ -393,7 +372,7 @@
 
 (*In general it seems wrong to add distributive laws by default: they
   might cause exponential blow-up.  But imp_disjL has been in for a while
-  and cannot be removed without affecting existing proofs.  Moreover, 
+  and cannot be removed without affecting existing proofs.  Moreover,
   rewriting by "(P|Q --> R) = ((P-->R)&(Q-->R))" might be justified on the
   grounds that it allows simplification of R in the two cases.*)
 
@@ -433,14 +412,16 @@
          eq_assume_tac, ematch_tac [FalseE]];
 val safe_solver = mk_solver "HOL safe" safe_solver_tac;
 
-val HOL_basic_ss = empty_ss setsubgoaler asm_simp_tac
-			    setSSolver safe_solver
-			    setSolver  unsafe_solver
-			    setmksimps (mksimps mksimps_pairs)
-			    setmkeqTrue mk_eq_True;
+val HOL_basic_ss =
+  empty_ss setsubgoaler asm_simp_tac
+    setSSolver safe_solver
+    setSolver unsafe_solver
+    setmksimps (mksimps mksimps_pairs)
+    setmkeqTrue mk_eq_True
+    setmkcong mk_meta_cong;
 
-val HOL_ss = 
-    HOL_basic_ss addsimps 
+val HOL_ss =
+    HOL_basic_ss addsimps
      ([triv_forall_equality, (* prunes params *)
        True_implies_equals, (* prune asms `True' *)
        eta_contract_eq, (* prunes eta-expansions *)
@@ -486,7 +467,7 @@
   during unification.*)
 fun expand_case_tac P i =
     res_inst_tac [("P",P)] expand_case i THEN
-    Simp_tac (i+1) THEN 
+    Simp_tac (i+1) THEN
     Simp_tac i;
 
 (*This lemma restricts the effect of the rewrite rule u=v to the left-hand
@@ -496,9 +477,8 @@
 qed "restrict_to_left";
 
 (* default simpset *)
-val simpsetup = 
-    [fn thy => (simpset_ref_of thy := HOL_ss addcongs [if_weak_cong]; 
-		thy)];
+val simpsetup =
+  [fn thy => (simpset_ref_of thy := HOL_ss addcongs [if_weak_cong]; thy)];
 
 
 (*** integration of simplifier with classical reasoner ***)
@@ -523,7 +503,7 @@
 
 
 (*** A general refutation procedure ***)
- 
+
 (* Parameters:
 
    test: term -> bool
--- a/src/Sequents/simpdata.ML	Tue Aug 29 00:54:22 2000 +0200
+++ b/src/Sequents/simpdata.ML	Tue Aug 29 00:55:31 2000 +0200
@@ -10,10 +10,10 @@
 
 (*** Rewrite rules ***)
 
-fun prove_fun s = 
- (writeln s;  
+fun prove_fun s =
+ (writeln s;
   prove_goal LK.thy s
-   (fn prems => [ (cut_facts_tac prems 1), 
+   (fn prems => [ (cut_facts_tac prems 1),
                   (fast_tac (pack() add_safes [subst]) 1) ]));
 
 val conj_simps = map prove_fun
@@ -34,7 +34,7 @@
 
 val imp_simps = map prove_fun
  ["|- (P --> False) <-> ~P",       "|- (P --> True) <-> True",
-  "|- (False --> P) <-> True",     "|- (True --> P) <-> P", 
+  "|- (False --> P) <-> True",     "|- (True --> P) <-> P",
   "|- (P --> P) <-> True",         "|- (P --> ~P) <-> ~P"];
 
 val iff_simps = map prove_fun
@@ -44,40 +44,40 @@
 
 
 val quant_simps = map prove_fun
- ["|- (ALL x. P) <-> P",   
+ ["|- (ALL x. P) <-> P",
   "|- (ALL x. x=t --> P(x)) <-> P(t)",
   "|- (ALL x. t=x --> P(x)) <-> P(t)",
   "|- (EX x. P) <-> P",
-  "|- (EX x. x=t & P(x)) <-> P(t)", 
+  "|- (EX x. x=t & P(x)) <-> P(t)",
   "|- (EX x. t=x & P(x)) <-> P(t)"];
 
 (*** Miniscoping: pushing quantifiers in
      We do NOT distribute of ALL over &, or dually that of EX over |
-     Baaz and Leitsch, On Skolemization and Proof Complexity (1994) 
+     Baaz and Leitsch, On Skolemization and Proof Complexity (1994)
      show that this step can increase proof length!
 ***)
 
 (*existential miniscoping*)
-val ex_simps = map prove_fun 
+val ex_simps = map prove_fun
                    ["|- (EX x. P(x) & Q) <-> (EX x. P(x)) & Q",
-		    "|- (EX x. P & Q(x)) <-> P & (EX x. Q(x))",
-		    "|- (EX x. P(x) | Q) <-> (EX x. P(x)) | Q",
-		    "|- (EX x. P | Q(x)) <-> P | (EX x. Q(x))",
-		    "|- (EX x. P(x) --> Q) <-> (ALL x. P(x)) --> Q",
-		    "|- (EX x. P --> Q(x)) <-> P --> (EX x. Q(x))"];
+                    "|- (EX x. P & Q(x)) <-> P & (EX x. Q(x))",
+                    "|- (EX x. P(x) | Q) <-> (EX x. P(x)) | Q",
+                    "|- (EX x. P | Q(x)) <-> P | (EX x. Q(x))",
+                    "|- (EX x. P(x) --> Q) <-> (ALL x. P(x)) --> Q",
+                    "|- (EX x. P --> Q(x)) <-> P --> (EX x. Q(x))"];
 
 (*universal miniscoping*)
 val all_simps = map prove_fun
                     ["|- (ALL x. P(x) & Q) <-> (ALL x. P(x)) & Q",
-		     "|- (ALL x. P & Q(x)) <-> P & (ALL x. Q(x))",
-		     "|- (ALL x. P(x) --> Q) <-> (EX x. P(x)) --> Q",
-		     "|- (ALL x. P --> Q(x)) <-> P --> (ALL x. Q(x))",
-		     "|- (ALL x. P(x) | Q) <-> (ALL x. P(x)) | Q",
-		     "|- (ALL x. P | Q(x)) <-> P | (ALL x. Q(x))"];
+                     "|- (ALL x. P & Q(x)) <-> P & (ALL x. Q(x))",
+                     "|- (ALL x. P(x) --> Q) <-> (EX x. P(x)) --> Q",
+                     "|- (ALL x. P --> Q(x)) <-> P --> (ALL x. Q(x))",
+                     "|- (ALL x. P(x) | Q) <-> (ALL x. P(x)) | Q",
+                     "|- (ALL x. P | Q(x)) <-> P | (ALL x. Q(x))"];
 
 (*These are NOT supplied by default!*)
 val distrib_simps  = map prove_fun
- ["|- P & (Q | R) <-> P&Q | P&R", 
+ ["|- P & (Q | R) <-> P&Q | P&R",
   "|- (Q | R) & P <-> Q&P | R&P",
   "|- (P | Q --> R) <-> (P --> R) & (Q --> R)"];
 
@@ -91,29 +91,29 @@
  case concl_of r of
    Const("Trueprop",_) $ Abs(_,_,a) $ Abs(_,_,c) =>
      (case (forms_of_seq a, forms_of_seq c) of
-	([], [p]) =>
-	  (case p of
-	       Const("op -->",_)$_$_ => atomize(r RS mp_R)
-	     | Const("op &",_)$_$_   => atomize(r RS conjunct1) @
-		   atomize(r RS conjunct2)
-	     | Const("All",_)$_      => atomize(r RS spec)
-	     | Const("True",_)       => []    (*True is DELETED*)
-	     | Const("False",_)      => []    (*should False do something?*)
-	     | _                     => [r])
+        ([], [p]) =>
+          (case p of
+               Const("op -->",_)$_$_ => atomize(r RS mp_R)
+             | Const("op &",_)$_$_   => atomize(r RS conjunct1) @
+                   atomize(r RS conjunct2)
+             | Const("All",_)$_      => atomize(r RS spec)
+             | Const("True",_)       => []    (*True is DELETED*)
+             | Const("False",_)      => []    (*should False do something?*)
+             | _                     => [r])
       | _ => [])  (*ignore theorem unless it has precisely one conclusion*)
  | _ => [r];
 
 
 Goal "|- ~P ==> |- (P <-> False)";
 by (etac (thinR RS cut) 1);
-by (Fast_tac 1);		
+by (Fast_tac 1);
 qed "P_iff_F";
 
 val iff_reflection_F = P_iff_F RS iff_reflection;
 
 Goal "|- P ==> |- (P <-> True)";
 by (etac (thinR RS cut) 1);
-by (Fast_tac 1);		
+by (Fast_tac 1);
 qed "P_iff_T";
 
 val iff_reflection_T = P_iff_T RS iff_reflection;
@@ -122,22 +122,23 @@
 fun mk_meta_eq th = case concl_of th of
     Const("==",_)$_$_           => th
   | Const("Trueprop",_) $ Abs(_,_,a) $ Abs(_,_,c) =>
-	(case (forms_of_seq a, forms_of_seq c) of
-	     ([], [p]) => 
-		 (case p of
-		      (Const("op =",_)$_$_)   => th RS eq_reflection
-		    | (Const("op <->",_)$_$_) => th RS iff_reflection
-		    | (Const("Not",_)$_)      => th RS iff_reflection_F
-		    | _                       => th RS iff_reflection_T)
-	   | _ => error ("addsimps: unable to use theorem\n" ^
-			 string_of_thm th));
+        (case (forms_of_seq a, forms_of_seq c) of
+             ([], [p]) =>
+                 (case p of
+                      (Const("op =",_)$_$_)   => th RS eq_reflection
+                    | (Const("op <->",_)$_$_) => th RS iff_reflection
+                    | (Const("Not",_)$_)      => th RS iff_reflection_F
+                    | _                       => th RS iff_reflection_T)
+           | _ => error ("addsimps: unable to use theorem\n" ^
+                         string_of_thm th));
 
 
 (*Replace premises x=y, X<->Y by X==Y*)
-val mk_meta_prems = 
-    rule_by_tactic 
+val mk_meta_prems =
+    rule_by_tactic
       (REPEAT_FIRST (resolve_tac [meta_eq_to_obj_eq, def_imp_iff]));
 
+(*Congruence rules for = or <-> (instead of ==)*)
 fun mk_meta_cong rl =
   standard(mk_meta_eq (mk_meta_prems rl))
   handle THM _ =>
@@ -147,7 +148,7 @@
 (*** Named rewrite rules ***)
 
 fun prove nm thm  = qed_goal nm LK.thy thm
-    (fn prems => [ (cut_facts_tac prems 1), 
+    (fn prems => [ (cut_facts_tac prems 1),
                    (fast_tac LK_pack 1) ]);
 
 prove "conj_commute" "|- P&Q <-> Q&P";
@@ -177,26 +178,26 @@
 prove "not_iff" "|- ~(P <-> Q) <-> (P <-> ~Q)";
 
 
-val [p1,p2] = Goal 
+val [p1,p2] = Goal
     "[| |- P <-> P';  |- P' ==> |- Q <-> Q' |] ==> |- (P-->Q) <-> (P'-->Q')";
 by (lemma_tac p1 1);
 by (Safe_tac 1);
-by (REPEAT (rtac cut 1 
-	    THEN
-	    DEPTH_SOLVE_1 (resolve_tac [thinL, thinR, p2 COMP monotonic] 1)
-	    THEN
-	    Safe_tac 1));
+by (REPEAT (rtac cut 1
+            THEN
+            DEPTH_SOLVE_1 (resolve_tac [thinL, thinR, p2 COMP monotonic] 1)
+            THEN
+            Safe_tac 1));
 qed "imp_cong";
 
-val [p1,p2] = Goal 
+val [p1,p2] = Goal
     "[| |- P <-> P';  |- P' ==> |- Q <-> Q' |] ==> |- (P&Q) <-> (P'&Q')";
 by (lemma_tac p1 1);
 by (Safe_tac 1);
-by (REPEAT (rtac cut 1 
-	    THEN
-	    DEPTH_SOLVE_1 (resolve_tac [thinL, thinR, p2 COMP monotonic] 1)
-	    THEN
-	    Safe_tac 1));
+by (REPEAT (rtac cut 1
+            THEN
+            DEPTH_SOLVE_1 (resolve_tac [thinL, thinR, p2 COMP monotonic] 1)
+            THEN
+            Safe_tac 1));
 qed "conj_cong";
 
 Goal "|- (x=y) <-> (y=x)";
@@ -229,32 +230,26 @@
 
 (*** Standard simpsets ***)
 
-(*Add congruence rules for = or <-> (instead of ==) *)
-infix 4 addcongs delcongs;
-fun ss addcongs congs = ss addeqcongs (map mk_meta_cong congs);
-fun ss delcongs congs = ss deleqcongs (map mk_meta_cong congs);
-
-fun Addcongs congs = (simpset_ref() := simpset() addcongs congs);
-fun Delcongs congs = (simpset_ref() := simpset() delcongs congs);
-
 val triv_rls = [FalseL, TrueR, basic, refl, iff_refl, reflexive_thm];
 
 fun unsafe_solver prems = FIRST'[resolve_tac (triv_rls@prems),
-				 assume_tac];
+                                 assume_tac];
 (*No premature instantiation of variables during simplification*)
 fun   safe_solver prems = FIRST'[fn i => DETERM (match_tac (triv_rls@prems) i),
-				 eq_assume_tac];
+                                 eq_assume_tac];
 
 (*No simprules, but basic infrastructure for simplification*)
-val LK_basic_ss = empty_ss setsubgoaler asm_simp_tac
-			   setSSolver   (mk_solver "safe" safe_solver)
-			   setSolver    (mk_solver "unsafe" unsafe_solver)
-			   setmksimps   (map mk_meta_eq o atomize o gen_all);
+val LK_basic_ss =
+  empty_ss setsubgoaler asm_simp_tac
+    setSSolver (mk_solver "safe" safe_solver)
+    setSolver (mk_solver "unsafe" unsafe_solver)
+    setmksimps (map mk_meta_eq o atomize o gen_all)
+    setmkcong mk_meta_cong;
 
 val LK_simps =
    [triv_forall_equality, (* prunes params *)
-    refl RS P_iff_T] @ 
-    conj_simps @ disj_simps @ not_simps @ 
+    refl RS P_iff_T] @
+    conj_simps @ disj_simps @ not_simps @
     imp_simps @ iff_simps @quant_simps @ all_simps @ ex_simps @
     [de_Morgan_conj, de_Morgan_disj, imp_disj1, imp_disj2] @
     map prove_fun
@@ -262,8 +257,10 @@
       "|- ~ ~ P <-> P",        "|- (~P --> P) <-> P",
       "|- (~P <-> ~Q) <-> (P<->Q)"];
 
-val LK_ss = LK_basic_ss addsimps LK_simps addeqcongs [left_cong]
-					  addcongs [imp_cong];
+val LK_ss =
+  LK_basic_ss addsimps LK_simps
+  addeqcongs [left_cong]
+  addcongs [imp_cong];
 
 simpset_ref() := LK_ss;