JDD: add Equiv BDD operation (dd1 <=> dd2)

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@11219 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/jdd/JDD.java

@@ -421,6 +421,15 @@ public class JDD
 		return ptrToNode(DD_Implies(dd1.ptr(), dd2.ptr()));
 	}
 	
+	/**
+	 * equivalence of dd1, dd2 (have to be 0/1-MTBDDs)
+	 * [ REFS: <i>result</i>, DEREFS: dd1, dd2 ]
+	 */
+	public static JDDNode Equiv(JDDNode dd1, JDDNode dd2)
+	{
+		return Not(Xor(dd1, dd2));
+	}
+	
 	/**
 	 * generic apply operation
 	 * <br>[ REFS: <i>result</i>, DEREFS: dd1, dd2 ]