only if 

英汉解释

只要……就；只是在……的时候

同义词

r. only，only when

参考例句

1. The Boolean operation whose result has the Boolean value 0 if and only if each operand has the Boolean value 0.
一种布尔运算，当且仅当每个操作数都具有布尔值0时，其结果才具有布尔值0。
2. China disrupt ties with Washington, that is good news. Now only if they stop trade. It would be the best news for our country.
中国跟华盛顿关系破裂，这是好事。现在要是他们停止贸易该多好。那对我们国家是最好的消息了。
3. Only if we grasp the absoluteness and relativity of the productivity standards, could we insist with scientific development views.
只有正确的把握生产力标准的绝对性与相对性，才能坚持科学的发展观。

英英解释

adv.
  1. never except when

网络释义

only if
也许只有; 只有; 仅仅如果; 唯有;
IF-AND-ONLY-IF operation
若且唯若运算;
IF-AND-ONLY-IF gate
若且唯若闸;
IF-AND-ONLY-IF element
若且唯若组件;
You're Only Lost If You C
独立摇滚;