approximation of the identity造句

例句与造句

1. But this is easy : it is known that \ | f _ r-f \ | _ 1 \ to 0 ( approximation of the identity ) and thus there is a subsequence f _ { r _ k } \ to f almost everywhere.
2. It's difficult to find approximation of the identity in a sentence. 用approximation of the identity造句挺难的