| author | paulson | 
| Tue, 16 Sep 1997 14:04:10 +0200 | |
| changeset 3675 | 70dd312b70b2 | 
| parent 289 | 78541329ff35 | 
| permissions | -rw-r--r-- | 
| 0 | 1  | 
(* Title: CCL/hered  | 
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ID: $Id$  | 
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Author: Martin Coen, Cambridge University Computer Laboratory  | 
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Copyright 1993 University of Cambridge  | 
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For hered.thy.  | 
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*)  | 
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open Hered;  | 
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fun type_of_terms (Const("Trueprop",_) $ (Const("op =",(Type ("fun", [t,_])))$_$_)) = t;
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(*** Hereditary Termination ***)  | 
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goalw Hered.thy [HTTgen_def] "mono(%X.HTTgen(X))";  | 
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br monoI 1;  | 
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by (fast_tac set_cs 1);  | 
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val HTTgen_mono = result();  | 
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goalw Hered.thy [HTTgen_def]  | 
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"t : HTTgen(A) <-> t=true | t=false | (EX a b.t=<a,b> & a : A & b : A) | \  | 
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\ (EX f.t=lam x.f(x) & (ALL x.f(x) : A))";  | 
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by (fast_tac set_cs 1);  | 
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val HTTgenXH = result();  | 
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goal Hered.thy  | 
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"t : HTT <-> t=true | t=false | (EX a b.t=<a,b> & a : HTT & b : HTT) | \  | 
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\ (EX f.t=lam x.f(x) & (ALL x.f(x) : HTT))";  | 
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br (rewrite_rule [HTTgen_def]  | 
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(HTTgen_mono RS (HTT_def RS def_gfp_Tarski) RS XHlemma1)) 1;  | 
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by (fast_tac set_cs 1);  | 
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val HTTXH = result();  | 
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(*** Introduction Rules for HTT ***)  | 
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goal Hered.thy "~ bot : HTT";  | 
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by (fast_tac (term_cs addDs [XH_to_D HTTXH]) 1);  | 
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val HTT_bot = result();  | 
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goal Hered.thy "true : HTT";  | 
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by (fast_tac (term_cs addIs [XH_to_I HTTXH]) 1);  | 
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val HTT_true = result();  | 
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goal Hered.thy "false : HTT";  | 
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by (fast_tac (term_cs addIs [XH_to_I HTTXH]) 1);  | 
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val HTT_false = result();  | 
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goal Hered.thy "<a,b> : HTT <-> a : HTT & b : HTT";  | 
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br (HTTXH RS iff_trans) 1;  | 
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by (fast_tac term_cs 1);  | 
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val HTT_pair = result();  | 
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goal Hered.thy "lam x.f(x) : HTT <-> (ALL x. f(x) : HTT)";  | 
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br (HTTXH RS iff_trans) 1;  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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by (simp_tac term_ss 1);  | 
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by (safe_tac term_cs);  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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by (asm_simp_tac term_ss 1);  | 
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by (fast_tac term_cs 1);  | 
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val HTT_lam = result();  | 
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local  | 
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val raw_HTTrews = [HTT_bot,HTT_true,HTT_false,HTT_pair,HTT_lam];  | 
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fun mk_thm s = prove_goalw Hered.thy data_defs s (fn _ =>  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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[simp_tac (term_ss addsimps raw_HTTrews) 1]);  | 
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in  | 
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val HTT_rews = raw_HTTrews @  | 
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map mk_thm ["one : HTT",  | 
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"inl(a) : HTT <-> a : HTT",  | 
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"inr(b) : HTT <-> b : HTT",  | 
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"zero : HTT",  | 
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"succ(n) : HTT <-> n : HTT",  | 
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"[] : HTT",  | 
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"x$xs : HTT <-> x : HTT & xs : HTT"];  | 
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end;  | 
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val HTT_Is = HTT_rews @ (HTT_rews RL [iffD2]);  | 
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(*** Coinduction for HTT ***)  | 
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val prems = goal Hered.thy "[| t : R; R <= HTTgen(R) |] ==> t : HTT";  | 
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br (HTT_def RS def_coinduct) 1;  | 
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by (REPEAT (ares_tac prems 1));  | 
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val HTT_coinduct = result();  | 
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fun HTT_coinduct_tac s i = res_inst_tac [("R",s)] HTT_coinduct i;
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val prems = goal Hered.thy  | 
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"[| t : R; R <= HTTgen(lfp(%x. HTTgen(x) Un R Un HTT)) |] ==> t : HTT";  | 
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br (HTTgen_mono RSN(3,HTT_def RS def_coinduct3)) 1;  | 
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by (REPEAT (ares_tac prems 1));  | 
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val HTT_coinduct3 = result();  | 
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val HTT_coinduct3_raw = rewrite_rule [HTTgen_def] HTT_coinduct3;  | 
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fun HTT_coinduct3_tac s i = res_inst_tac [("R",s)] HTT_coinduct3 i;
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val HTTgenIs = map (mk_genIs Hered.thy data_defs HTTgenXH HTTgen_mono)  | 
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["true : HTTgen(R)",  | 
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"false : HTTgen(R)",  | 
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"[| a : R; b : R |] ==> <a,b> : HTTgen(R)",  | 
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"[| !!x. b(x) : R |] ==> lam x.b(x) : HTTgen(R)",  | 
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"one : HTTgen(R)",  | 
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"a : lfp(%x. HTTgen(x) Un R Un HTT) ==> \  | 
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\ inl(a) : HTTgen(lfp(%x. HTTgen(x) Un R Un HTT))",  | 
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"b : lfp(%x. HTTgen(x) Un R Un HTT) ==> \  | 
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\ inr(b) : HTTgen(lfp(%x. HTTgen(x) Un R Un HTT))",  | 
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"zero : HTTgen(lfp(%x. HTTgen(x) Un R Un HTT))",  | 
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"n : lfp(%x. HTTgen(x) Un R Un HTT) ==> \  | 
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\ succ(n) : HTTgen(lfp(%x. HTTgen(x) Un R Un HTT))",  | 
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"[] : HTTgen(lfp(%x. HTTgen(x) Un R Un HTT))",  | 
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"[| h : lfp(%x. HTTgen(x) Un R Un HTT); t : lfp(%x. HTTgen(x) Un R Un HTT) |] ==>\  | 
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\ h$t : HTTgen(lfp(%x. HTTgen(x) Un R Un HTT))"];  | 
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(*** Formation Rules for Types ***)  | 
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goal Hered.thy "Unit <= HTT";  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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by (simp_tac (CCL_ss addsimps ([subsetXH,UnitXH] @ HTT_rews)) 1);  | 
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val UnitF = result();  | 
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goal Hered.thy "Bool <= HTT";  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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by (simp_tac (CCL_ss addsimps ([subsetXH,BoolXH] @ HTT_rews)) 1);  | 
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by (fast_tac (set_cs addIs HTT_Is @ (prems RL [subsetD])) 1);  | 
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val BoolF = result();  | 
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val prems = goal Hered.thy "[| A <= HTT; B <= HTT |] ==> A + B <= HTT";  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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by (simp_tac (CCL_ss addsimps ([subsetXH,PlusXH] @ HTT_rews)) 1);  | 
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by (fast_tac (set_cs addIs HTT_Is @ (prems RL [subsetD])) 1);  | 
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val PlusF = result();  | 
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val prems = goal Hered.thy  | 
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"[| A <= HTT; !!x.x:A ==> B(x) <= HTT |] ==> SUM x:A.B(x) <= HTT";  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
131  | 
by (simp_tac (CCL_ss addsimps ([subsetXH,SgXH] @ HTT_rews)) 1);  | 
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by (fast_tac (set_cs addIs HTT_Is @ (prems RL [subsetD])) 1);  | 
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val SigmaF = result();  | 
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(*** Formation Rules for Recursive types - using coinduction these only need ***)  | 
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(*** exhaution rule for type-former ***)  | 
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(*Proof by induction - needs induction rule for type*)  | 
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goal Hered.thy "Nat <= HTT";  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
140  | 
by (simp_tac (term_ss addsimps [subsetXH]) 1);  | 
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by (safe_tac set_cs);  | 
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be Nat_ind 1;  | 
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by (ALLGOALS (fast_tac (set_cs addIs HTT_Is @ (prems RL [subsetD]))));  | 
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val NatF = result();  | 
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goal Hered.thy "Nat <= HTT";  | 
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by (safe_tac set_cs);  | 
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be HTT_coinduct3 1;  | 
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by (fast_tac (set_cs addIs HTTgenIs  | 
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addSEs [HTTgen_mono RS ci3_RI] addEs [XH_to_E NatXH]) 1);  | 
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val NatF = result();  | 
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val [prem] = goal Hered.thy "A <= HTT ==> List(A) <= HTT";  | 
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by (safe_tac set_cs);  | 
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be HTT_coinduct3 1;  | 
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by (fast_tac (set_cs addSIs HTTgenIs  | 
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addSEs [HTTgen_mono RS ci3_RI,prem RS subsetD RS (HTTgen_mono RS ci3_AI)]  | 
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addEs [XH_to_E ListXH]) 1);  | 
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val ListF = result();  | 
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val [prem] = goal Hered.thy "A <= HTT ==> Lists(A) <= HTT";  | 
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by (safe_tac set_cs);  | 
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be HTT_coinduct3 1;  | 
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by (fast_tac (set_cs addSIs HTTgenIs  | 
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addSEs [HTTgen_mono RS ci3_RI,prem RS subsetD RS (HTTgen_mono RS ci3_AI)]  | 
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addEs [XH_to_E ListsXH]) 1);  | 
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val ListsF = result();  | 
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val [prem] = goal Hered.thy "A <= HTT ==> ILists(A) <= HTT";  | 
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by (safe_tac set_cs);  | 
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be HTT_coinduct3 1;  | 
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by (fast_tac (set_cs addSIs HTTgenIs  | 
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addSEs [HTTgen_mono RS ci3_RI,prem RS subsetD RS (HTTgen_mono RS ci3_AI)]  | 
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addEs [XH_to_E IListsXH]) 1);  | 
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val IListsF = result();  | 
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(*** A possible use for this predicate is proving equality from pre-order ***)  | 
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(*** but it seems as easy (and more general) to do this directly by coinduction ***)  | 
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(*  | 
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val prems = goal Hered.thy "[| t : HTT; t [= u |] ==> u [= t";  | 
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by (po_coinduct_tac "{p. EX a b.p=<a,b> & b : HTT & b [= a}" 1);
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by (fast_tac (ccl_cs addIs prems) 1);  | 
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by (safe_tac ccl_cs);  | 
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bd (poXH RS iffD1) 1;  | 
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by (safe_tac (set_cs addSEs [HTT_bot RS notE]));  | 
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by (REPEAT_SOME (rtac (POgenXH RS iffD2) ORELSE' etac rev_mp));  | 
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8
 
c3d2c6dcf3f0
Installation of new simplfier.  Previously appeared to set up the old
 
lcp 
parents: 
0 
diff
changeset
 | 
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by (ALLGOALS (simp_tac (term_ss addsimps HTT_rews)));  | 
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by (ALLGOALS (fast_tac ccl_cs));  | 
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val HTT_po_op = result();  | 
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val prems = goal Hered.thy "[| t : HTT; t [= u |] ==> t = u";  | 
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by (REPEAT (ares_tac (prems @ [conjI RS (eq_iff RS iffD2),HTT_po_op]) 1));  | 
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val HTT_po_eq = result();  | 
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*)  |