CHALLENGE rule randomly generates challenges.

src/dk/itu/mario/level/grammar/LevelGrammarFactory.java

@@ -83,6 +83,9 @@ public class LevelGrammarFactory {
 		}
 		
 		String remainder = clause.substring(rBraceIndex);
+		if (remainder.startsWith("}, ")) {
+			remainder = remainder.substring(3);
+		}
 		List<String> rhsClauseStrings = new ArrayList<String>();
 		if (remainder.contains("(")) {
 			int nextLeftIndex = -1;