If( X, a) is a pair of symbols of any context free grammar, then there is at most one generalized precedence relation between X aad a.是什么意思_If( X, a) is a pair of symbols of any context free grammar, then there is at most one generalized precedence relation between X aad a.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句