extended expressions attributes

src/main/jastadd/base/clauses/expressions.jadd

@@ -8,6 +8,18 @@ aspect SignalExpressions {
     syn boolean Literal.isNegativeLiteral() = false;
     eq NegativeLiteral.isNegativeLiteral() = true;
 
+    syn boolean InputSignalClause.hasLiteral(java.lang.String signalId){
+
+        for(Disjunction d : this.getDisjunctions()){
+            for(Literal l : d.getLiterals()){
+                if(l.getName().equals(signalId)){
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
     syn String ASTNode.printClause();
     eq ASTNode.printClause() = "";
     eq Literal.printClause() = getName();