(* Title: ZF/simpdata
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1991 University of Cambridge
Rewriting for ZF set theory: specialized extraction of rewrites from theorems
*)
(*** New version of mk_rew_rules ***)
(*Should False yield False<->True, or should it solve goals some other way?*)
(*Analyse a theorem to atomic rewrite rules*)
fun atomize (conn_pairs, mem_pairs) th =
let fun tryrules pairs t =
case head_of t of
Const(a,_) =>
(case assoc(pairs,a) of
Some rls => flat (map (atomize (conn_pairs, mem_pairs))
([th] RL rls))
| None => [th])
| _ => [th]
in case concl_of th of
Const("Trueprop",_) $ P =>
(case P of
Const("op :",_) $ a $ b => tryrules mem_pairs b
| Const("True",_) => []
| Const("False",_) => []
| A => tryrules conn_pairs A)
| _ => [th]
end;
(*Analyse a rigid formula*)
val ZF_conn_pairs =
[("Ball", [bspec]),
("All", [spec]),
("op -->", [mp]),
("op &", [conjunct1,conjunct2])];
(*Analyse a:b, where b is rigid*)
val ZF_mem_pairs =
[("Collect", [CollectD1,CollectD2]),
("op -", [DiffD1,DiffD2]),
("op Int", [IntD1,IntD2])];
val ZF_atomize = atomize (ZF_conn_pairs, ZF_mem_pairs);
simpset_ref() := simpset() setmksimps (map mk_eq o ZF_atomize o gen_all)
addcongs [if_weak_cong]
addsplits [split_if]
setSolver (mk_solver "types" Type_solver_tac);
(** Splitting IFs in the assumptions **)
Goal "P(if Q then x else y) <-> (~((Q & ~P(x)) | (~Q & ~P(y))))";
by (Simp_tac 1);
qed "split_if_asm";
bind_thms ("if_splits", [split_if, split_if_asm]);
(*** Miniscoping: pushing in big Unions, Intersections, quantifiers, etc. ***)
local
(*For proving rewrite rules*)
fun prover s = (print s;prove_goalw (the_context ()) [Inter_def] s
(fn _ => [Simp_tac 1,
ALLGOALS (blast_tac (claset() addSIs[equalityI]))]));
in
val ball_simps = map prover
["(ALL x:A. P(x) | Q) <-> ((ALL x:A. P(x)) | Q)",
"(ALL x:A. P | Q(x)) <-> (P | (ALL x:A. Q(x)))",
"(ALL x:A. P --> Q(x)) <-> (P --> (ALL x:A. Q(x)))",
"(ALL x:A. P(x) --> Q) <-> ((EX x:A. P(x)) --> Q)",
"(ALL x:0.P(x)) <-> True",
"(ALL x:succ(i).P(x)) <-> P(i) & (ALL x:i. P(x))",
"(ALL x:cons(a,B).P(x)) <-> P(a) & (ALL x:B. P(x))",
"(ALL x:RepFun(A,f). P(x)) <-> (ALL y:A. P(f(y)))",
"(ALL x:Union(A).P(x)) <-> (ALL y:A. ALL x:y. P(x))",
"(ALL x:Collect(A,Q).P(x)) <-> (ALL x:A. Q(x) --> P(x))",
"(~(ALL x:A. P(x))) <-> (EX x:A. ~P(x))"];
val ball_conj_distrib =
prover "(ALL x:A. P(x) & Q(x)) <-> ((ALL x:A. P(x)) & (ALL x:A. Q(x)))";
val bex_simps = map prover
["(EX x:A. P(x) & Q) <-> ((EX x:A. P(x)) & Q)",
"(EX x:A. P & Q(x)) <-> (P & (EX x:A. Q(x)))",
"(EX x:0.P(x)) <-> False",
"(EX x:succ(i).P(x)) <-> P(i) | (EX x:i. P(x))",
"(EX x:cons(a,B).P(x)) <-> P(a) | (EX x:B. P(x))",
"(EX x:RepFun(A,f). P(x)) <-> (EX y:A. P(f(y)))",
"(EX x:Union(A).P(x)) <-> (EX y:A. EX x:y. P(x))",
"(EX x:Collect(A,Q).P(x)) <-> (EX x:A. Q(x) & P(x))",
"(~(EX x:A. P(x))) <-> (ALL x:A. ~P(x))"];
val bex_disj_distrib =
prover "(EX x:A. P(x) | Q(x)) <-> ((EX x:A. P(x)) | (EX x:A. Q(x)))";
val Rep_simps = map prover
["{x. y:0, R(x,y)} = 0", (*Replace*)
"{x:0. P(x)} = 0", (*Collect*)
"{x:A. False} = 0",
"{x:A. True} = A",
"RepFun(0,f) = 0", (*RepFun*)
"RepFun(succ(i),f) = cons(f(i), RepFun(i,f))",
"RepFun(cons(a,B),f) = cons(f(a), RepFun(B,f))"]
val misc_simps = map prover
["0 Un A = A", "A Un 0 = A",
"0 Int A = 0", "A Int 0 = 0",
"0 - A = 0", "A - 0 = A",
"Union(0) = 0",
"Union(cons(b,A)) = b Un Union(A)",
"Inter({b}) = b"]
val UN_simps = map prover
["(UN x:C. cons(a, B(x))) = (if C=0 then 0 else cons(a, UN x:C. B(x)))",
"(UN x:C. A(x) Un B) = (if C=0 then 0 else (UN x:C. A(x)) Un B)",
"(UN x:C. A Un B(x)) = (if C=0 then 0 else A Un (UN x:C. B(x)))",
"(UN x:C. A(x) Int B) = ((UN x:C. A(x)) Int B)",
"(UN x:C. A Int B(x)) = (A Int (UN x:C. B(x)))",
"(UN x:C. A(x) - B) = ((UN x:C. A(x)) - B)",
"(UN x:C. A - B(x)) = (if C=0 then 0 else A - (INT x:C. B(x)))",
"(UN x: Union(A). B(x)) = (UN y:A. UN x:y. B(x))",
"(UN z: (UN x:A. B(x)). C(z)) = (UN x:A. UN z: B(x). C(z))",
"(UN x: RepFun(A,f). B(x)) = (UN a:A. B(f(a)))"];
val INT_simps = map prover
["(INT x:C. A(x) Int B) = (INT x:C. A(x)) Int B",
"(INT x:C. A Int B(x)) = A Int (INT x:C. B(x))",
"(INT x:C. A(x) - B) = (INT x:C. A(x)) - B",
"(INT x:C. A - B(x)) = (if C=0 then 0 else A - (UN x:C. B(x)))",
"(INT x:C. cons(a, B(x))) = (if C=0 then 0 else cons(a, INT x:C. B(x)))",
"(INT x:C. A(x) Un B) = (if C=0 then 0 else (INT x:C. A(x)) Un B)",
"(INT x:C. A Un B(x)) = (if C=0 then 0 else A Un (INT x:C. B(x)))"];
(** The _extend_simps rules are oriented in the opposite direction, to
pull UN and INT outwards. **)
val UN_extend_simps = map prover
["cons(a, UN x:C. B(x)) = (if C=0 then {a} else (UN x:C. cons(a, B(x))))",
"(UN x:C. A(x)) Un B = (if C=0 then B else (UN x:C. A(x) Un B))",
"A Un (UN x:C. B(x)) = (if C=0 then A else (UN x:C. A Un B(x)))",
"((UN x:C. A(x)) Int B) = (UN x:C. A(x) Int B)",
"(A Int (UN x:C. B(x))) = (UN x:C. A Int B(x))",
"((UN x:C. A(x)) - B) = (UN x:C. A(x) - B)",
"A - (INT x:C. B(x)) = (if C=0 then A else (UN x:C. A - B(x)))",
"(UN y:A. UN x:y. B(x)) = (UN x: Union(A). B(x))",
"(UN x:A. UN z: B(x). C(z)) = (UN z: (UN x:A. B(x)). C(z))",
"(UN a:A. B(f(a))) = (UN x: RepFun(A,f). B(x))"];
val INT_extend_simps = map prover
["(INT x:C. A(x)) Int B = (INT x:C. A(x) Int B)",
"A Int (INT x:C. B(x)) = (INT x:C. A Int B(x))",
"(INT x:C. A(x)) - B = (INT x:C. A(x) - B)",
"A - (UN x:C. B(x)) = (if C=0 then A else (INT x:C. A - B(x)))",
"cons(a, INT x:C. B(x)) = (if C=0 then {a} else (INT x:C. cons(a, B(x))))",
"(INT x:C. A(x)) Un B = (if C=0 then B else (INT x:C. A(x) Un B))",
"A Un (INT x:C. B(x)) = (if C=0 then A else (INT x:C. A Un B(x)))"];
end;
bind_thms ("ball_simps", ball_simps);
bind_thm ("ball_conj_distrib", ball_conj_distrib);
bind_thms ("bex_simps", bex_simps);
bind_thm ("bex_disj_distrib", bex_disj_distrib);
bind_thms ("Rep_simps", Rep_simps);
bind_thms ("misc_simps", misc_simps);
Addsimps (ball_simps @ bex_simps @ Rep_simps @ misc_simps);
bind_thms ("UN_simps", UN_simps);
bind_thms ("INT_simps", INT_simps);
Addsimps (UN_simps @ INT_simps);
bind_thms ("UN_extend_simps", UN_extend_simps);
bind_thms ("INT_extend_simps", INT_extend_simps);
(** One-point rule for bounded quantifiers: see HOL/Set.ML **)
Goal "(EX x:A. x=a) <-> (a:A)";
by (Blast_tac 1);
qed "bex_triv_one_point1";
Goal "(EX x:A. a=x) <-> (a:A)";
by (Blast_tac 1);
qed "bex_triv_one_point2";
Goal "(EX x:A. x=a & P(x)) <-> (a:A & P(a))";
by (Blast_tac 1);
qed "bex_one_point1";
Goal "(EX x:A. a=x & P(x)) <-> (a:A & P(a))";
by(Blast_tac 1);
qed "bex_one_point2";
Goal "(ALL x:A. x=a --> P(x)) <-> (a:A --> P(a))";
by (Blast_tac 1);
qed "ball_one_point1";
Goal "(ALL x:A. a=x --> P(x)) <-> (a:A --> P(a))";
by (Blast_tac 1);
qed "ball_one_point2";
Addsimps [bex_triv_one_point1,bex_triv_one_point2,
bex_one_point1,bex_one_point2,
ball_one_point1,ball_one_point2];
let
val ex_pattern = Thm.read_cterm (Theory.sign_of (the_context ()))
("EX x:A. P(x) & Q(x)",FOLogic.oT)
val prove_bex_tac = rewrite_goals_tac [Bex_def] THEN
Quantifier1.prove_one_point_ex_tac;
val rearrange_bex = Quantifier1.rearrange_bex prove_bex_tac;
val all_pattern = Thm.read_cterm (Theory.sign_of (the_context ()))
("ALL x:A. P(x) --> Q(x)",FOLogic.oT)
val prove_ball_tac = rewrite_goals_tac [Ball_def] THEN
Quantifier1.prove_one_point_all_tac;
val rearrange_ball = Quantifier1.rearrange_ball prove_ball_tac;
val defBEX_regroup = mk_simproc "defined BEX" [ex_pattern] rearrange_bex;
val defBALL_regroup = mk_simproc "defined BALL" [all_pattern] rearrange_ball;
in
Addsimprocs [defBALL_regroup,defBEX_regroup]
end;
val ZF_ss = simpset();