be difficult of proof的意思|示意

Since proof is difficult, we may even concede that the results of anxiety may sometimes, from certain points of view, be desirable.

因为取证困难，我们甚至可能承认焦虑的后果，可能有时从某些观点来看，是值得的。

This article had not been finished yet, but the method of torment had been changed to be more hidden and more difficult to find proof. If I told it to people, it became more unbelievable.

这篇文章还没写完，折磨的方法已经变了，变得更隐蔽，更难找到证据，说出来更没有可信性。

The court may estimate the extent of damage where proof of the exact amount would be too difficult or too costly.

在证明损害的精确数额过于困难或费用过高时，法院可以评估损害的范围。