Fixed very obscure MTBDD round-off bug.

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@132 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/prism/Modules2MTBDD.java

@@ -1634,7 +1634,7 @@ public class Modules2MTBDD
 		
 		// find the max number of overlaps
 		// (i.e. max number of nondet. choices)
-		maxChoices = (int)JDD.FindMax(overlaps);
+		maxChoices = (int)Math.round(JDD.FindMax(overlaps));
 		
 		// if all the guards were false, we're done already
 		if (maxChoices == 0) {