fixed issue #355: wrapped guard expression in parenthesis expression

before combining with trigger expression.

plugins/org.yakindu.sct.model.sexec/src/org/yakindu/sct/model/sexec/transformation/BehaviorMapping.xtend

@@ -730,7 +730,7 @@ class BehaviorMapping {
 		
 		val guard = t.buildGuard
 		
-		if ( triggerCheck != null && guard != null )  stext.and(stext.parenthesis(triggerCheck), guard)
+		if ( triggerCheck != null && guard != null )  stext.and(stext.parenthesis(triggerCheck), stext.parenthesis(guard))
 		else if ( triggerCheck != null )  triggerCheck
 		else guard
 	}