src/HOL/Isar_examples/ExprCompiler.thy
changeset 7480 0a0e0dbe1269
parent 7253 a494a78fea39
child 7565 bfa85f429629
--- a/src/HOL/Isar_examples/ExprCompiler.thy	Sat Sep 04 21:12:15 1999 +0200
+++ b/src/HOL/Isar_examples/ExprCompiler.thy	Sat Sep 04 21:13:01 1999 +0200
@@ -100,30 +100,30 @@
 *};
 
 lemma exec_append:
-  "ALL stack. exec (xs @ ys) stack env = exec ys (exec xs stack env) env" (is "??P xs");
-proof (induct ??P xs type: list);
-  show "??P []"; by simp;
+  "ALL stack. exec (xs @ ys) stack env = exec ys (exec xs stack env) env" (is "?P xs");
+proof (induct ?P xs type: list);
+  show "?P []"; by simp;
 
   fix x xs;
-  assume "??P xs";
-  show "??P (x # xs)" (is "??Q x");
-  proof (induct ??Q x type: instr);
-    fix val; show "??Q (Const val)"; by force;
+  assume "?P xs";
+  show "?P (x # xs)" (is "?Q x");
+  proof (induct ?Q x type: instr);
+    fix val; show "?Q (Const val)"; by force;
   next;
-    fix adr; show "??Q (Load adr)"; by force;
+    fix adr; show "?Q (Load adr)"; by force;
   next;
-    fix fun; show "??Q (Apply fun)"; by force;
+    fix fun; show "?Q (Apply fun)"; by force;
   qed;
 qed;
 
 lemma exec_comp:
-  "ALL stack. exec (comp e) stack env = eval e env # stack" (is "??P e");
-proof (induct ??P e type: expr);
-  fix adr; show "??P (Variable adr)"; by force;
+  "ALL stack. exec (comp e) stack env = eval e env # stack" (is "?P e");
+proof (induct ?P e type: expr);
+  fix adr; show "?P (Variable adr)"; by force;
 next;
-  fix val; show "??P (Constant val)"; by force;
+  fix val; show "?P (Constant val)"; by force;
 next;
-  fix fun e1 e2; assume "??P e1" "??P e2"; show "??P (Binop fun e1 e2)";
+  fix fun e1 e2; assume "?P e1" "?P e2"; show "?P (Binop fun e1 e2)";
     by (force simp add: exec_append);
 qed;