ex/Acc.ML
changeset 252 a4dc62a46ee4
parent 251 f04b33ce250f
child 253 132634d24019
--- a/ex/Acc.ML	Tue Oct 24 14:59:17 1995 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,63 +0,0 @@
-(*  Title: 	HOL/ex/Acc
-    ID:         $Id$
-    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
-    Copyright   1994  University of Cambridge
-
-Inductive definition of acc(r)
-
-See Ch. Paulin-Mohring, Inductive Definitions in the System Coq.
-Research Report 92-49, LIP, ENS Lyon.  Dec 1992.
-*)
-
-open Acc;
-
-(*The intended introduction rule*)
-val prems = goal Acc.thy
-    "[| !!b. <b,a>:r ==> b: acc(r) |] ==> a: acc(r)";
-by (fast_tac (set_cs addIs (prems @ 
-			    map (rewrite_rule [pred_def]) acc.intrs)) 1);
-qed "accI";
-
-goal Acc.thy "!!a b r. [| b: acc(r);  <a,b>: r |] ==> a: acc(r)";
-by (etac acc.elim 1);
-by (rewtac pred_def);
-by (fast_tac set_cs 1);
-qed "acc_downward";
-
-val [major,indhyp] = goal Acc.thy
-    "[| a : acc(r);						\
-\       !!x. [| x: acc(r);  ALL y. <y,x>:r --> P(y) |] ==> P(x)	\
-\    |] ==> P(a)";
-by (rtac (major RS acc.induct) 1);
-by (rtac indhyp 1);
-by (resolve_tac acc.intrs 1);
-by (rewtac pred_def);
-by (fast_tac set_cs 2);
-by (etac (Int_lower1 RS Pow_mono RS subsetD) 1);
-qed "acc_induct";
-
-
-val [major] = goal Acc.thy "r <= Sigma(acc(r), %u. acc(r)) ==> wf(r)";
-by (rtac (major RS wfI) 1);
-by (etac acc.induct 1);
-by (rewtac pred_def);
-by (fast_tac set_cs 1);
-qed "acc_wfI";
-
-val [major] = goal Acc.thy "wf(r) ==> ALL x. <x,y>: r | <y,x>:r --> y: acc(r)";
-by (rtac (major RS wf_induct) 1);
-by (rtac (impI RS allI) 1);
-by (rtac accI 1);
-by (fast_tac set_cs 1);
-qed "acc_wfD_lemma";
-
-val [major] = goal Acc.thy "wf(r) ==> r <= Sigma(acc(r), %u. acc(r))";
-by (rtac subsetI 1);
-by (res_inst_tac [("p", "x")] PairE 1);
-by (fast_tac (set_cs addSIs [SigmaI,
-			     major RS acc_wfD_lemma RS spec RS mp]) 1);
-qed "acc_wfD";
-
-goal Acc.thy "wf(r)  =  (r <= Sigma(acc(r), %u. acc(r)))";
-by (EVERY1 [rtac iffI, etac acc_wfD, etac acc_wfI]);
-qed "wf_acc_iff";