public static List yieldFlattenedArguments(Proposition proposition, List existsvariables) {
    { List flattenedarguments = List.newList();

      Proposition.helpCollectFlattenedArguments(proposition, flattenedarguments, existsvariables);
      flattenedarguments.push(proposition);
      existsvariables.reverse();
      return (flattenedarguments.reverse());
    }
  }