make error message more resilient

jastadd-mquat-base/src/main/jastadd/Eval.jrag

@@ -67,9 +67,8 @@ aspect eval {
     }
     if (providingAssignment == null) {
       MquatWriteSettings settings = new MquatWriteSettings("");
-      logger.error("Could not evaluate {} in {} of {}",
-        this.print(settings), containingClause().print(settings),
-    ((ModelElement)containingClause().getParent()).name());
+      logger.error("Could not evaluate {} in {}",
+        this.print(settings), containingClause().print(settings));
       return 0;
     }
     for (Clause clause : providingAssignment.getImplementation().getClauseList()) {