extended set comprehension notation with {pttrn : A . P}
(* Title: FOLP/IFOLP.thy
Author: Martin D Coen, Cambridge University Computer Laboratory
Copyright 1992 University of Cambridge
*)
header {* Intuitionistic First-Order Logic with Proofs *}
theory IFOLP
imports Pure
begin
ML_file "~~/src/Tools/misc_legacy.ML"
setup Pure_Thy.old_appl_syntax_setup
classes "term"
default_sort "term"
typedecl p
typedecl o
consts
(*** Judgements ***)
Proof :: "[o,p]=>prop"
EqProof :: "[p,p,o]=>prop" ("(3_ /= _ :/ _)" [10,10,10] 5)
(*** Logical Connectives -- Type Formers ***)
eq :: "['a,'a] => o" (infixl "=" 50)
True :: "o"
False :: "o"
Not :: "o => o" ("~ _" [40] 40)
conj :: "[o,o] => o" (infixr "&" 35)
disj :: "[o,o] => o" (infixr "|" 30)
imp :: "[o,o] => o" (infixr "-->" 25)
iff :: "[o,o] => o" (infixr "<->" 25)
(*Quantifiers*)
All :: "('a => o) => o" (binder "ALL " 10)
Ex :: "('a => o) => o" (binder "EX " 10)
Ex1 :: "('a => o) => o" (binder "EX! " 10)
(*Rewriting gadgets*)
NORM :: "o => o"
norm :: "'a => 'a"
(*** Proof Term Formers: precedence must exceed 50 ***)
tt :: "p"
contr :: "p=>p"
fst :: "p=>p"
snd :: "p=>p"
pair :: "[p,p]=>p" ("(1<_,/_>)")
split :: "[p, [p,p]=>p] =>p"
inl :: "p=>p"
inr :: "p=>p"
when :: "[p, p=>p, p=>p]=>p"
lambda :: "(p => p) => p" (binder "lam " 55)
App :: "[p,p]=>p" (infixl "`" 60)
alll :: "['a=>p]=>p" (binder "all " 55)
app :: "[p,'a]=>p" (infixl "^" 55)
exists :: "['a,p]=>p" ("(1[_,/_])")
xsplit :: "[p,['a,p]=>p]=>p"
ideq :: "'a=>p"
idpeel :: "[p,'a=>p]=>p"
nrm :: p
NRM :: p
syntax "_Proof" :: "[p,o]=>prop" ("(_ /: _)" [51, 10] 5)
parse_translation {*
let fun proof_tr [p, P] = Const (@{const_syntax Proof}, dummyT) $ P $ p
in [(@{syntax_const "_Proof"}, proof_tr)] end
*}
(*show_proofs = true displays the proof terms -- they are ENORMOUS*)
ML {* val show_proofs = Attrib.setup_config_bool @{binding show_proofs} (K false) *}
print_translation (advanced) {*
let
fun proof_tr' ctxt [P, p] =
if Config.get ctxt show_proofs then Const (@{syntax_const "_Proof"}, dummyT) $ p $ P
else P
in [(@{const_syntax Proof}, proof_tr')] end
*}
(**** Propositional logic ****)
(*Equality*)
(* Like Intensional Equality in MLTT - but proofs distinct from terms *)
axiomatization where
ieqI: "ideq(a) : a=a" and
ieqE: "[| p : a=b; !!x. f(x) : P(x,x) |] ==> idpeel(p,f) : P(a,b)"
(* Truth and Falsity *)
axiomatization where
TrueI: "tt : True" and
FalseE: "a:False ==> contr(a):P"
(* Conjunction *)
axiomatization where
conjI: "[| a:P; b:Q |] ==> <a,b> : P&Q" and
conjunct1: "p:P&Q ==> fst(p):P" and
conjunct2: "p:P&Q ==> snd(p):Q"
(* Disjunction *)
axiomatization where
disjI1: "a:P ==> inl(a):P|Q" and
disjI2: "b:Q ==> inr(b):P|Q" and
disjE: "[| a:P|Q; !!x. x:P ==> f(x):R; !!x. x:Q ==> g(x):R
|] ==> when(a,f,g):R"
(* Implication *)
axiomatization where
impI: "\<And>P Q f. (!!x. x:P ==> f(x):Q) ==> lam x. f(x):P-->Q" and
mp: "\<And>P Q f. [| f:P-->Q; a:P |] ==> f`a:Q"
(*Quantifiers*)
axiomatization where
allI: "\<And>P. (!!x. f(x) : P(x)) ==> all x. f(x) : ALL x. P(x)" and
spec: "\<And>P f. (f:ALL x. P(x)) ==> f^x : P(x)"
axiomatization where
exI: "p : P(x) ==> [x,p] : EX x. P(x)" and
exE: "[| p: EX x. P(x); !!x u. u:P(x) ==> f(x,u) : R |] ==> xsplit(p,f):R"
(**** Equality between proofs ****)
axiomatization where
prefl: "a : P ==> a = a : P" and
psym: "a = b : P ==> b = a : P" and
ptrans: "[| a = b : P; b = c : P |] ==> a = c : P"
axiomatization where
idpeelB: "[| !!x. f(x) : P(x,x) |] ==> idpeel(ideq(a),f) = f(a) : P(a,a)"
axiomatization where
fstB: "a:P ==> fst(<a,b>) = a : P" and
sndB: "b:Q ==> snd(<a,b>) = b : Q" and
pairEC: "p:P&Q ==> p = <fst(p),snd(p)> : P&Q"
axiomatization where
whenBinl: "[| a:P; !!x. x:P ==> f(x) : Q |] ==> when(inl(a),f,g) = f(a) : Q" and
whenBinr: "[| b:P; !!x. x:P ==> g(x) : Q |] ==> when(inr(b),f,g) = g(b) : Q" and
plusEC: "a:P|Q ==> when(a,%x. inl(x),%y. inr(y)) = a : P|Q"
axiomatization where
applyB: "[| a:P; !!x. x:P ==> b(x) : Q |] ==> (lam x. b(x)) ` a = b(a) : Q" and
funEC: "f:P ==> f = lam x. f`x : P"
axiomatization where
specB: "[| !!x. f(x) : P(x) |] ==> (all x. f(x)) ^ a = f(a) : P(a)"
(**** Definitions ****)
defs
not_def: "~P == P-->False"
iff_def: "P<->Q == (P-->Q) & (Q-->P)"
(*Unique existence*)
ex1_def: "EX! x. P(x) == EX x. P(x) & (ALL y. P(y) --> y=x)"
(*Rewriting -- special constants to flag normalized terms and formulae*)
axiomatization where
norm_eq: "nrm : norm(x) = x" and
NORM_iff: "NRM : NORM(P) <-> P"
(*** Sequent-style elimination rules for & --> and ALL ***)
schematic_lemma conjE:
assumes "p:P&Q"
and "!!x y.[| x:P; y:Q |] ==> f(x,y):R"
shows "?a:R"
apply (rule assms(2))
apply (rule conjunct1 [OF assms(1)])
apply (rule conjunct2 [OF assms(1)])
done
schematic_lemma impE:
assumes "p:P-->Q"
and "q:P"
and "!!x. x:Q ==> r(x):R"
shows "?p:R"
apply (rule assms mp)+
done
schematic_lemma allE:
assumes "p:ALL x. P(x)"
and "!!y. y:P(x) ==> q(y):R"
shows "?p:R"
apply (rule assms spec)+
done
(*Duplicates the quantifier; for use with eresolve_tac*)
schematic_lemma all_dupE:
assumes "p:ALL x. P(x)"
and "!!y z.[| y:P(x); z:ALL x. P(x) |] ==> q(y,z):R"
shows "?p:R"
apply (rule assms spec)+
done
(*** Negation rules, which translate between ~P and P-->False ***)
schematic_lemma notI:
assumes "!!x. x:P ==> q(x):False"
shows "?p:~P"
unfolding not_def
apply (assumption | rule assms impI)+
done
schematic_lemma notE: "p:~P \<Longrightarrow> q:P \<Longrightarrow> ?p:R"
unfolding not_def
apply (drule (1) mp)
apply (erule FalseE)
done
(*This is useful with the special implication rules for each kind of P. *)
schematic_lemma not_to_imp:
assumes "p:~P"
and "!!x. x:(P-->False) ==> q(x):Q"
shows "?p:Q"
apply (assumption | rule assms impI notE)+
done
(* For substitution int an assumption P, reduce Q to P-->Q, substitute into
this implication, then apply impI to move P back into the assumptions.*)
schematic_lemma rev_mp: "[| p:P; q:P --> Q |] ==> ?p:Q"
apply (assumption | rule mp)+
done
(*Contrapositive of an inference rule*)
schematic_lemma contrapos:
assumes major: "p:~Q"
and minor: "!!y. y:P==>q(y):Q"
shows "?a:~P"
apply (rule major [THEN notE, THEN notI])
apply (erule minor)
done
(** Unique assumption tactic.
Ignores proof objects.
Fails unless one assumption is equal and exactly one is unifiable
**)
ML {*
local
fun discard_proof (Const (@{const_name Proof}, _) $ P $ _) = P;
in
val uniq_assume_tac =
SUBGOAL
(fn (prem,i) =>
let val hyps = map discard_proof (Logic.strip_assums_hyp prem)
and concl = discard_proof (Logic.strip_assums_concl prem)
in
if exists (fn hyp => hyp aconv concl) hyps
then case distinct (op =) (filter (fn hyp => Term.could_unify (hyp, concl)) hyps) of
[_] => assume_tac i
| _ => no_tac
else no_tac
end);
end;
*}
(*** Modus Ponens Tactics ***)
(*Finds P-->Q and P in the assumptions, replaces implication by Q *)
ML {*
fun mp_tac i = eresolve_tac [@{thm notE}, make_elim @{thm mp}] i THEN assume_tac i
*}
(*Like mp_tac but instantiates no variables*)
ML {*
fun int_uniq_mp_tac i = eresolve_tac [@{thm notE}, @{thm impE}] i THEN uniq_assume_tac i
*}
(*** If-and-only-if ***)
schematic_lemma iffI:
assumes "!!x. x:P ==> q(x):Q"
and "!!x. x:Q ==> r(x):P"
shows "?p:P<->Q"
unfolding iff_def
apply (assumption | rule assms conjI impI)+
done
(*Observe use of rewrite_rule to unfold "<->" in meta-assumptions (prems) *)
schematic_lemma iffE:
assumes "p:P <-> Q"
and "!!x y.[| x:P-->Q; y:Q-->P |] ==> q(x,y):R"
shows "?p:R"
apply (rule conjE)
apply (rule assms(1) [unfolded iff_def])
apply (rule assms(2))
apply assumption+
done
(* Destruct rules for <-> similar to Modus Ponens *)
schematic_lemma iffD1: "[| p:P <-> Q; q:P |] ==> ?p:Q"
unfolding iff_def
apply (rule conjunct1 [THEN mp], assumption+)
done
schematic_lemma iffD2: "[| p:P <-> Q; q:Q |] ==> ?p:P"
unfolding iff_def
apply (rule conjunct2 [THEN mp], assumption+)
done
schematic_lemma iff_refl: "?p:P <-> P"
apply (rule iffI)
apply assumption+
done
schematic_lemma iff_sym: "p:Q <-> P ==> ?p:P <-> Q"
apply (erule iffE)
apply (rule iffI)
apply (erule (1) mp)+
done
schematic_lemma iff_trans: "[| p:P <-> Q; q:Q<-> R |] ==> ?p:P <-> R"
apply (rule iffI)
apply (assumption | erule iffE | erule (1) impE)+
done
(*** Unique existence. NOTE THAT the following 2 quantifications
EX!x such that [EX!y such that P(x,y)] (sequential)
EX!x,y such that P(x,y) (simultaneous)
do NOT mean the same thing. The parser treats EX!x y.P(x,y) as sequential.
***)
schematic_lemma ex1I:
assumes "p:P(a)"
and "!!x u. u:P(x) ==> f(u) : x=a"
shows "?p:EX! x. P(x)"
unfolding ex1_def
apply (assumption | rule assms exI conjI allI impI)+
done
schematic_lemma ex1E:
assumes "p:EX! x. P(x)"
and "!!x u v. [| u:P(x); v:ALL y. P(y) --> y=x |] ==> f(x,u,v):R"
shows "?a : R"
apply (insert assms(1) [unfolded ex1_def])
apply (erule exE conjE | assumption | rule assms(1))+
apply (erule assms(2), assumption)
done
(*** <-> congruence rules for simplification ***)
(*Use iffE on a premise. For conj_cong, imp_cong, all_cong, ex_cong*)
ML {*
fun iff_tac prems i =
resolve_tac (prems RL [@{thm iffE}]) i THEN
REPEAT1 (eresolve_tac [asm_rl, @{thm mp}] i)
*}
schematic_lemma conj_cong:
assumes "p:P <-> P'"
and "!!x. x:P' ==> q(x):Q <-> Q'"
shows "?p:(P&Q) <-> (P'&Q')"
apply (insert assms(1))
apply (assumption | rule iffI conjI |
erule iffE conjE mp | tactic {* iff_tac @{thms assms} 1 *})+
done
schematic_lemma disj_cong:
"[| p:P <-> P'; q:Q <-> Q' |] ==> ?p:(P|Q) <-> (P'|Q')"
apply (erule iffE disjE disjI1 disjI2 | assumption | rule iffI | tactic {* mp_tac 1 *})+
done
schematic_lemma imp_cong:
assumes "p:P <-> P'"
and "!!x. x:P' ==> q(x):Q <-> Q'"
shows "?p:(P-->Q) <-> (P'-->Q')"
apply (insert assms(1))
apply (assumption | rule iffI impI | erule iffE | tactic {* mp_tac 1 *} |
tactic {* iff_tac @{thms assms} 1 *})+
done
schematic_lemma iff_cong:
"[| p:P <-> P'; q:Q <-> Q' |] ==> ?p:(P<->Q) <-> (P'<->Q')"
apply (erule iffE | assumption | rule iffI | tactic {* mp_tac 1 *})+
done
schematic_lemma not_cong:
"p:P <-> P' ==> ?p:~P <-> ~P'"
apply (assumption | rule iffI notI | tactic {* mp_tac 1 *} | erule iffE notE)+
done
schematic_lemma all_cong:
assumes "!!x. f(x):P(x) <-> Q(x)"
shows "?p:(ALL x. P(x)) <-> (ALL x. Q(x))"
apply (assumption | rule iffI allI | tactic {* mp_tac 1 *} | erule allE |
tactic {* iff_tac @{thms assms} 1 *})+
done
schematic_lemma ex_cong:
assumes "!!x. f(x):P(x) <-> Q(x)"
shows "?p:(EX x. P(x)) <-> (EX x. Q(x))"
apply (erule exE | assumption | rule iffI exI | tactic {* mp_tac 1 *} |
tactic {* iff_tac @{thms assms} 1 *})+
done
(*NOT PROVED
bind_thm ("ex1_cong", prove_goal (the_context ())
"(!!x.f(x):P(x) <-> Q(x)) ==> ?p:(EX! x.P(x)) <-> (EX! x.Q(x))"
(fn prems =>
[ (REPEAT (eresolve_tac [ex1E, spec RS mp] 1 ORELSE ares_tac [iffI,ex1I] 1
ORELSE mp_tac 1
ORELSE iff_tac prems 1)) ]))
*)
(*** Equality rules ***)
lemmas refl = ieqI
schematic_lemma subst:
assumes prem1: "p:a=b"
and prem2: "q:P(a)"
shows "?p : P(b)"
apply (rule prem2 [THEN rev_mp])
apply (rule prem1 [THEN ieqE])
apply (rule impI)
apply assumption
done
schematic_lemma sym: "q:a=b ==> ?c:b=a"
apply (erule subst)
apply (rule refl)
done
schematic_lemma trans: "[| p:a=b; q:b=c |] ==> ?d:a=c"
apply (erule (1) subst)
done
(** ~ b=a ==> ~ a=b **)
schematic_lemma not_sym: "p:~ b=a ==> ?q:~ a=b"
apply (erule contrapos)
apply (erule sym)
done
schematic_lemma ssubst: "p:b=a \<Longrightarrow> q:P(a) \<Longrightarrow> ?p:P(b)"
apply (drule sym)
apply (erule subst)
apply assumption
done
(*A special case of ex1E that would otherwise need quantifier expansion*)
schematic_lemma ex1_equalsE: "[| p:EX! x. P(x); q:P(a); r:P(b) |] ==> ?d:a=b"
apply (erule ex1E)
apply (rule trans)
apply (rule_tac [2] sym)
apply (assumption | erule spec [THEN mp])+
done
(** Polymorphic congruence rules **)
schematic_lemma subst_context: "[| p:a=b |] ==> ?d:t(a)=t(b)"
apply (erule ssubst)
apply (rule refl)
done
schematic_lemma subst_context2: "[| p:a=b; q:c=d |] ==> ?p:t(a,c)=t(b,d)"
apply (erule ssubst)+
apply (rule refl)
done
schematic_lemma subst_context3: "[| p:a=b; q:c=d; r:e=f |] ==> ?p:t(a,c,e)=t(b,d,f)"
apply (erule ssubst)+
apply (rule refl)
done
(*Useful with eresolve_tac for proving equalties from known equalities.
a = b
| |
c = d *)
schematic_lemma box_equals: "[| p:a=b; q:a=c; r:b=d |] ==> ?p:c=d"
apply (rule trans)
apply (rule trans)
apply (rule sym)
apply assumption+
done
(*Dual of box_equals: for proving equalities backwards*)
schematic_lemma simp_equals: "[| p:a=c; q:b=d; r:c=d |] ==> ?p:a=b"
apply (rule trans)
apply (rule trans)
apply (assumption | rule sym)+
done
(** Congruence rules for predicate letters **)
schematic_lemma pred1_cong: "p:a=a' ==> ?p:P(a) <-> P(a')"
apply (rule iffI)
apply (tactic {* DEPTH_SOLVE (atac 1 ORELSE eresolve_tac [@{thm subst}, @{thm ssubst}] 1) *})
done
schematic_lemma pred2_cong: "[| p:a=a'; q:b=b' |] ==> ?p:P(a,b) <-> P(a',b')"
apply (rule iffI)
apply (tactic {* DEPTH_SOLVE (atac 1 ORELSE eresolve_tac [@{thm subst}, @{thm ssubst}] 1) *})
done
schematic_lemma pred3_cong: "[| p:a=a'; q:b=b'; r:c=c' |] ==> ?p:P(a,b,c) <-> P(a',b',c')"
apply (rule iffI)
apply (tactic {* DEPTH_SOLVE (atac 1 ORELSE eresolve_tac [@{thm subst}, @{thm ssubst}] 1) *})
done
lemmas pred_congs = pred1_cong pred2_cong pred3_cong
(*special case for the equality predicate!*)
lemmas eq_cong = pred2_cong [where P = "op ="]
(*** Simplifications of assumed implications.
Roy Dyckhoff has proved that conj_impE, disj_impE, and imp_impE
used with mp_tac (restricted to atomic formulae) is COMPLETE for
intuitionistic propositional logic. See
R. Dyckhoff, Contraction-free sequent calculi for intuitionistic logic
(preprint, University of St Andrews, 1991) ***)
schematic_lemma conj_impE:
assumes major: "p:(P&Q)-->S"
and minor: "!!x. x:P-->(Q-->S) ==> q(x):R"
shows "?p:R"
apply (assumption | rule conjI impI major [THEN mp] minor)+
done
schematic_lemma disj_impE:
assumes major: "p:(P|Q)-->S"
and minor: "!!x y.[| x:P-->S; y:Q-->S |] ==> q(x,y):R"
shows "?p:R"
apply (tactic {* DEPTH_SOLVE (atac 1 ORELSE
resolve_tac [@{thm disjI1}, @{thm disjI2}, @{thm impI},
@{thm major} RS @{thm mp}, @{thm minor}] 1) *})
done
(*Simplifies the implication. Classical version is stronger.
Still UNSAFE since Q must be provable -- backtracking needed. *)
schematic_lemma imp_impE:
assumes major: "p:(P-->Q)-->S"
and r1: "!!x y.[| x:P; y:Q-->S |] ==> q(x,y):Q"
and r2: "!!x. x:S ==> r(x):R"
shows "?p:R"
apply (assumption | rule impI major [THEN mp] r1 r2)+
done
(*Simplifies the implication. Classical version is stronger.
Still UNSAFE since ~P must be provable -- backtracking needed. *)
schematic_lemma not_impE:
assumes major: "p:~P --> S"
and r1: "!!y. y:P ==> q(y):False"
and r2: "!!y. y:S ==> r(y):R"
shows "?p:R"
apply (assumption | rule notI impI major [THEN mp] r1 r2)+
done
(*Simplifies the implication. UNSAFE. *)
schematic_lemma iff_impE:
assumes major: "p:(P<->Q)-->S"
and r1: "!!x y.[| x:P; y:Q-->S |] ==> q(x,y):Q"
and r2: "!!x y.[| x:Q; y:P-->S |] ==> r(x,y):P"
and r3: "!!x. x:S ==> s(x):R"
shows "?p:R"
apply (assumption | rule iffI impI major [THEN mp] r1 r2 r3)+
done
(*What if (ALL x.~~P(x)) --> ~~(ALL x.P(x)) is an assumption? UNSAFE*)
schematic_lemma all_impE:
assumes major: "p:(ALL x. P(x))-->S"
and r1: "!!x. q:P(x)"
and r2: "!!y. y:S ==> r(y):R"
shows "?p:R"
apply (assumption | rule allI impI major [THEN mp] r1 r2)+
done
(*Unsafe: (EX x.P(x))-->S is equivalent to ALL x.P(x)-->S. *)
schematic_lemma ex_impE:
assumes major: "p:(EX x. P(x))-->S"
and r: "!!y. y:P(a)-->S ==> q(y):R"
shows "?p:R"
apply (assumption | rule exI impI major [THEN mp] r)+
done
schematic_lemma rev_cut_eq:
assumes "p:a=b"
and "!!x. x:a=b ==> f(x):R"
shows "?p:R"
apply (rule assms)+
done
lemma thin_refl: "!!X. [|p:x=x; PROP W|] ==> PROP W" .
ML_file "hypsubst.ML"
ML {*
structure Hypsubst = Hypsubst
(
(*Take apart an equality judgement; otherwise raise Match!*)
fun dest_eq (Const (@{const_name Proof}, _) $
(Const (@{const_name eq}, _) $ t $ u) $ _) = (t, u);
val imp_intr = @{thm impI}
(*etac rev_cut_eq moves an equality to be the last premise. *)
val rev_cut_eq = @{thm rev_cut_eq}
val rev_mp = @{thm rev_mp}
val subst = @{thm subst}
val sym = @{thm sym}
val thin_refl = @{thm thin_refl}
);
open Hypsubst;
*}
ML_file "intprover.ML"
(*** Rewrite rules ***)
schematic_lemma conj_rews:
"?p1 : P & True <-> P"
"?p2 : True & P <-> P"
"?p3 : P & False <-> False"
"?p4 : False & P <-> False"
"?p5 : P & P <-> P"
"?p6 : P & ~P <-> False"
"?p7 : ~P & P <-> False"
"?p8 : (P & Q) & R <-> P & (Q & R)"
apply (tactic {* fn st => IntPr.fast_tac 1 st *})+
done
schematic_lemma disj_rews:
"?p1 : P | True <-> True"
"?p2 : True | P <-> True"
"?p3 : P | False <-> P"
"?p4 : False | P <-> P"
"?p5 : P | P <-> P"
"?p6 : (P | Q) | R <-> P | (Q | R)"
apply (tactic {* IntPr.fast_tac 1 *})+
done
schematic_lemma not_rews:
"?p1 : ~ False <-> True"
"?p2 : ~ True <-> False"
apply (tactic {* IntPr.fast_tac 1 *})+
done
schematic_lemma imp_rews:
"?p1 : (P --> False) <-> ~P"
"?p2 : (P --> True) <-> True"
"?p3 : (False --> P) <-> True"
"?p4 : (True --> P) <-> P"
"?p5 : (P --> P) <-> True"
"?p6 : (P --> ~P) <-> ~P"
apply (tactic {* IntPr.fast_tac 1 *})+
done
schematic_lemma iff_rews:
"?p1 : (True <-> P) <-> P"
"?p2 : (P <-> True) <-> P"
"?p3 : (P <-> P) <-> True"
"?p4 : (False <-> P) <-> ~P"
"?p5 : (P <-> False) <-> ~P"
apply (tactic {* IntPr.fast_tac 1 *})+
done
schematic_lemma quant_rews:
"?p1 : (ALL x. P) <-> P"
"?p2 : (EX x. P) <-> P"
apply (tactic {* IntPr.fast_tac 1 *})+
done
(*These are NOT supplied by default!*)
schematic_lemma distrib_rews1:
"?p1 : ~(P|Q) <-> ~P & ~Q"
"?p2 : P & (Q | R) <-> P&Q | P&R"
"?p3 : (Q | R) & P <-> Q&P | R&P"
"?p4 : (P | Q --> R) <-> (P --> R) & (Q --> R)"
apply (tactic {* IntPr.fast_tac 1 *})+
done
schematic_lemma distrib_rews2:
"?p1 : ~(EX x. NORM(P(x))) <-> (ALL x. ~NORM(P(x)))"
"?p2 : ((EX x. NORM(P(x))) --> Q) <-> (ALL x. NORM(P(x)) --> Q)"
"?p3 : (EX x. NORM(P(x))) & NORM(Q) <-> (EX x. NORM(P(x)) & NORM(Q))"
"?p4 : NORM(Q) & (EX x. NORM(P(x))) <-> (EX x. NORM(Q) & NORM(P(x)))"
apply (tactic {* IntPr.fast_tac 1 *})+
done
lemmas distrib_rews = distrib_rews1 distrib_rews2
schematic_lemma P_Imp_P_iff_T: "p:P ==> ?p:(P <-> True)"
apply (tactic {* IntPr.fast_tac 1 *})
done
schematic_lemma not_P_imp_P_iff_F: "p:~P ==> ?p:(P <-> False)"
apply (tactic {* IntPr.fast_tac 1 *})
done
end