diff -r 000000000000 -r a5a9c433f639 src/ZF/domrange.ML --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/ZF/domrange.ML Thu Sep 16 12:20:38 1993 +0200 @@ -0,0 +1,229 @@ +(* Title: ZF/domrange + ID: $Id$ + Author: Lawrence C Paulson, Cambridge University Computer Laboratory + Copyright 1991 University of Cambridge + +Converse, domain, range of a relation or function +*) + +(*** converse ***) + +val converseI = prove_goalw ZF.thy [converse_def] + "!!a b r. :r ==> :converse(r)" + (fn _ => [ (fast_tac pair_cs 1) ]); + +val converseD = prove_goalw ZF.thy [converse_def] + "!!a b r. : converse(r) ==> : r" + (fn _ => [ (fast_tac pair_cs 1) ]); + +val converseE = prove_goalw ZF.thy [converse_def] + "[| yx : converse(r); \ +\ !!x y. [| yx=; :r |] ==> P \ +\ |] ==> P" + (fn [major,minor]=> + [ (rtac (major RS ReplaceE) 1), + (REPEAT (eresolve_tac [exE, conjE, minor] 1)), + (hyp_subst_tac 1), + (assume_tac 1) ]); + +val converse_cs = pair_cs addSIs [converseI] + addSEs [converseD,converseE]; + +val converse_of_converse = prove_goal ZF.thy + "!!A B r. r<=Sigma(A,B) ==> converse(converse(r)) = r" + (fn _ => [ (fast_tac (converse_cs addSIs [equalityI]) 1) ]); + +val converse_type = prove_goal ZF.thy "!!A B r. r<=A*B ==> converse(r)<=B*A" + (fn _ => [ (fast_tac converse_cs 1) ]); + +val converse_of_prod = prove_goal ZF.thy "converse(A*B) = B*A" + (fn _ => [ (fast_tac (converse_cs addSIs [equalityI]) 1) ]); + +val converse_empty = prove_goal ZF.thy "converse(0) = 0" + (fn _ => [ (fast_tac (converse_cs addSIs [equalityI]) 1) ]); + +(*** domain ***) + +val domain_iff = prove_goalw ZF.thy [domain_def] + "a: domain(r) <-> (EX y. : r)" + (fn _=> [ (fast_tac pair_cs 1) ]); + +val domainI = prove_goal ZF.thy "!!a b r. : r ==> a: domain(r)" + (fn _ => [ (etac (exI RS (domain_iff RS iffD2)) 1) ]); + +val domainE = prove_goal ZF.thy + "[| a : domain(r); !!y. : r ==> P |] ==> P" + (fn prems=> + [ (rtac (domain_iff RS iffD1 RS exE) 1), + (REPEAT (ares_tac prems 1)) ]); + +val domain_of_prod = prove_goal ZF.thy "!!A B. b:B ==> domain(A*B) = A" + (fn _ => + [ (REPEAT (eresolve_tac [domainE,SigmaE2] 1 + ORELSE ares_tac [domainI,equalityI,subsetI,SigmaI] 1)) ]); + +val domain_empty = prove_goal ZF.thy "domain(0) = 0" + (fn _ => + [ (REPEAT (eresolve_tac [domainE,emptyE] 1 + ORELSE ares_tac [equalityI,subsetI] 1)) ]); + +val domain_subset = prove_goal ZF.thy "domain(Sigma(A,B)) <= A" + (fn _ => + [ (rtac subsetI 1), + (etac domainE 1), + (etac SigmaD1 1) ]); + + +(*** range ***) + +val rangeI = prove_goalw ZF.thy [range_def] "!!a b r.: r ==> b : range(r)" + (fn _ => [ (etac (converseI RS domainI) 1) ]); + +val rangeE = prove_goalw ZF.thy [range_def] + "[| b : range(r); !!x. : r ==> P |] ==> P" + (fn major::prems=> + [ (rtac (major RS domainE) 1), + (resolve_tac prems 1), + (etac converseD 1) ]); + +val range_of_prod = prove_goalw ZF.thy [range_def] + "!!a A B. a:A ==> range(A*B) = B" + (fn _ => + [ (rtac (converse_of_prod RS ssubst) 1), + (etac domain_of_prod 1) ]); + +val range_empty = prove_goalw ZF.thy [range_def] "range(0) = 0" + (fn _ => + [ (rtac (converse_empty RS ssubst) 1), + (rtac domain_empty 1) ]); + +val range_subset = prove_goalw ZF.thy [range_def] "range(A*B) <= B" + (fn _ => + [ (rtac (converse_of_prod RS ssubst) 1), + (rtac domain_subset 1) ]); + + +(*** field ***) + +val fieldI1 = prove_goalw ZF.thy [field_def] ": r ==> a : field(r)" + (fn [prem]=> + [ (rtac (prem RS domainI RS UnI1) 1) ]); + +val fieldI2 = prove_goalw ZF.thy [field_def] ": r ==> b : field(r)" + (fn [prem]=> + [ (rtac (prem RS rangeI RS UnI2) 1) ]); + +val fieldCI = prove_goalw ZF.thy [field_def] + "(~ :r ==> : r) ==> a : field(r)" + (fn [prem]=> + [ (rtac (prem RS domainI RS UnCI) 1), + (swap_res_tac [rangeI] 1), + (etac notnotD 1) ]); + +val fieldE = prove_goalw ZF.thy [field_def] + "[| a : field(r); \ +\ !!x. : r ==> P; \ +\ !!x. : r ==> P |] ==> P" + (fn major::prems=> + [ (rtac (major RS UnE) 1), + (REPEAT (eresolve_tac (prems@[domainE,rangeE]) 1)) ]); + +val field_of_prod = prove_goal ZF.thy "field(A*A) = A" + (fn _ => + [ (fast_tac (pair_cs addIs [fieldCI,equalityI] addSEs [fieldE]) 1) ]); + +val field_subset = prove_goal ZF.thy "field(A*B) <= A Un B" + (fn _ => [ (fast_tac (pair_cs addIs [fieldCI] addSEs [fieldE]) 1) ]); + +val domain_subset_field = prove_goalw ZF.thy [field_def] + "domain(r) <= field(r)" + (fn _ => [ (rtac Un_upper1 1) ]); + +val range_subset_field = prove_goalw ZF.thy [field_def] + "range(r) <= field(r)" + (fn _ => [ (rtac Un_upper2 1) ]); + +val domain_times_range = prove_goal ZF.thy + "!!A B r. r <= Sigma(A,B) ==> r <= domain(r)*range(r)" + (fn _ => [ (fast_tac (pair_cs addIs [domainI,rangeI]) 1) ]); + +val field_times_field = prove_goal ZF.thy + "!!A B r. r <= Sigma(A,B) ==> r <= field(r)*field(r)" + (fn _ => [ (fast_tac (pair_cs addIs [fieldI1,fieldI2]) 1) ]); + + +(*** Image of a set under a function/relation ***) + +val image_iff = prove_goalw ZF.thy [image_def] + "b : r``A <-> (EX x:A. :r)" + (fn _ => [ fast_tac (pair_cs addIs [rangeI]) 1 ]); + +val image_singleton_iff = prove_goal ZF.thy + "b : r``{a} <-> :r" + (fn _ => [ rtac (image_iff RS iff_trans) 1, + fast_tac pair_cs 1 ]); + +val imageI = prove_goalw ZF.thy [image_def] + "!!a b r. [| : r; a:A |] ==> b : r``A" + (fn _ => [ (REPEAT (ares_tac [CollectI,rangeI,bexI] 1)) ]); + +val imageE = prove_goalw ZF.thy [image_def] + "[| b: r``A; !!x.[| : r; x:A |] ==> P |] ==> P" + (fn major::prems=> + [ (rtac (major RS CollectE) 1), + (REPEAT (etac bexE 1 ORELSE ares_tac prems 1)) ]); + +val image_subset = prove_goal ZF.thy + "!!A B r. [| r <= A*B; C<=A |] ==> r``C <= B" + (fn _ => + [ (rtac subsetI 1), + (REPEAT (eresolve_tac [asm_rl, imageE, subsetD RS SigmaD2] 1)) ]); + + +(*** Inverse image of a set under a function/relation ***) + +val vimage_iff = prove_goalw ZF.thy [vimage_def,image_def,converse_def] + "a : r-``B <-> (EX y:B. :r)" + (fn _ => [ fast_tac (pair_cs addIs [rangeI]) 1 ]); + +val vimage_singleton_iff = prove_goal ZF.thy + "a : r-``{b} <-> :r" + (fn _ => [ rtac (vimage_iff RS iff_trans) 1, + fast_tac pair_cs 1 ]); + +val vimageI = prove_goalw ZF.thy [vimage_def] + "!!A B r. [| : r; b:B |] ==> a : r-``B" + (fn _ => [ (REPEAT (ares_tac [converseI RS imageI] 1)) ]); + +val vimageE = prove_goalw ZF.thy [vimage_def] + "[| a: r-``B; !!x.[| : r; x:B |] ==> P |] ==> P" + (fn major::prems=> + [ (rtac (major RS imageE) 1), + (REPEAT (etac converseD 1 ORELSE ares_tac prems 1)) ]); + +val vimage_subset = prove_goalw ZF.thy [vimage_def] + "!!A B r. [| r <= A*B; C<=B |] ==> r-``C <= A" + (fn _ => [ (REPEAT (ares_tac [converse_type RS image_subset] 1)) ]); + + +(** Theorem-proving for ZF set theory **) + +val ZF_cs = pair_cs + addSIs [converseI] + addIs [imageI, vimageI, domainI, rangeI, fieldCI] + addSEs [imageE, vimageE, domainE, rangeE, fieldE, converseD, converseE]; + +val eq_cs = ZF_cs addSIs [equalityI]; + +(** The Union of a set of relations is a relation -- Lemma for fun_Union **) +goal ZF.thy "!!S. (ALL x:S. EX A B. x <= A*B) ==> \ +\ Union(S) <= domain(Union(S)) * range(Union(S))"; +by (fast_tac ZF_cs 1); +val rel_Union = result(); + +(** The Union of 2 relations is a relation (Lemma for fun_Un) **) +val rel_Un = prove_goal ZF.thy + "!!r s. [| r <= A*B; s <= C*D |] ==> (r Un s) <= (A Un C) * (B Un D)" + (fn _ => [ (fast_tac ZF_cs 1) ]); + +