in so far as 的用法

in so far as 为什么老师讲的时候是“至于...，就...而言”，它的英文解释却是to the extent that，到...的程度，没有"就...而言"的解释啊。而在NCE4中
In so far as any inquiry is a secret one, it naturally limits all those engaged in carrying it out from effective contact with their fellow scientist either in other countries or...
老师的解释是相当于since，同样词典上也没有这个解释，不会有些牵强吗？
请解释一下in so far as的意义，谢谢

to the
extent that
达到……的程度以致；就……来说；在这个意义上；在这样的范围内；在……方面来说

so long as只要 you may eat anything, so long as you don't eat too much. 只要不吃得太多，你可以吃任何东西。 as far as就...而言,至于,远到 as far as i am concerned, i'm not against your plan. 就我而言，我并不反对你的计划。 so far as就...说(到...的程度) so far as english is concerned, it is not so difficult as you might think. 就英文而言，它并不像你所认为的那样难。

in so far as = insofar as = to that degree = to that extent 表示到了某种程度