很多NN在做逻辑的时候都会使用取非的方法来做选择，想问一下取非的原则是什么呢？例如下面一句，取非以后会是什么样的呢？

Money contributed by individuals who make their donations because provisions in the federal tax laws provides the only source of funding for many charitable and educational institutions.

另外想再请教“a pattern of cause and effect”怎么翻译？

取非：Money contributed by individuals who make their donations because provisions in the federal tax laws does not provide the only source of funding for many charitable and educational institutions.

a pattern of cause and effect：一种因果关系。