static bool writeNode(std::string &retVal, const OperationDAG &dag, const OperationDAGNode &node, std::map< VariableKey, std::string > &varBindings, std::set< const OperationDAGNode * > &alreadyHandled, int &tempVarCount, std::set< const OperationDAGNode * > ¤tlyHandling, std::map< std::string, std::string > *opReplace=NULL, std::vector< std::string > *varReplacements=NULL)