diff -r 69032a618aa9 -r d14c4e9e9c8e src/HOL/MicroJava/JVM/Opstack.thy
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/HOL/MicroJava/JVM/Opstack.thy	Thu Nov 11 12:23:45 1999 +0100
@@ -0,0 +1,38 @@
+(*  Title:      HOL/MicroJava/JVM/Opstack.thy
+    ID:         $Id$
+    Author:     Cornelia Pusch
+    Copyright   1999 Technische Universitaet Muenchen
+
+Manipulation of operand stack
+*)
+
+Opstack = JVMState +
+
+(** instructions for the direct manipulation of the operand stack **)
+
+datatype 
+ op_stack = 
+   Pop
+ | Dup
+ | Dup_x1
+ | Dup_x2
+ | Swap
+	  
+consts
+ exec_os :: "[op_stack,opstack,p_count] \\<Rightarrow> (opstack \\<times> p_count)" 
+
+primrec 
+  "exec_os Pop stk pc = (tl stk , pc+1)"
+
+  "exec_os Dup stk pc = (hd stk # stk , pc+1)"
+
+  "exec_os Dup_x1 stk pc = (hd stk # hd (tl stk) # hd stk # (tl (tl stk)) , pc+1)"
+
+  "exec_os Dup_x2 stk pc = (hd stk # hd (tl stk) # (hd (tl (tl stk))) # hd stk # (tl (tl (tl stk))) , pc+1)"
+
+  "exec_os Swap stk pc = 
+	(let (val1,val2) = (hd stk,hd (tl stk))
+	 in
+	 (val2#val1#(tl (tl stk)) , pc+1))"
+
+end