恒等定理的英文：
identity theorem
n. 身份；同一性；一致；特性；个性；恒等式
Your appearance is identical to hers.
你的相貌和她的一模一样。
They're wearing identical clothes.
他们穿着完全相同的衣服。
The police have no clue to his identity.
警察没有可以确定他的身份的任何线索。
We reach an identity of views.
我们取得完全一致的看法。
These two designs are almost identical.
这两种式样几乎完全相同。
n. 【术语】（尤指数学）定理
The theorem may be explained as follows.
这条原理可以这样来阐述。
As a particular of Rado's theorem and the compactness theorem one obtains the following result
作为Rado定理和紧致性定理的一种特殊情形，我们得到下面的结果。
In his book he gave definitions and theorems but no proofs
在他的书中他给出定义和定理但无证明。
All this leads up to the most fundamental of theorems of calculus.
综上所述就导出了微积分学中的最基本的定理。
The assertion is known as the closed graph theorem for Hilbert spaces.
这个断语被称为希耳伯特空间的闭图象定理。