The distinction between covariance and contravariance is important for computations with tensors, which often have mixed variance.

协变和逆变的区别对于张量的计算尤为重要，这往往会出现混合方差。

In the meantime, I further elucidated the compatibility, incompatibility and contravariance of the mathematical concept.

同时，还进一步阐明了数学概念的兼容性、非兼容性和反变性。

Note that although the above examples show how to declare covariance and contravariance for delegate types, it's not different to do so with interfaces.

注意尽管上面的例子只展示了对于代理类型如何声明协变和逆变。对于接口这样做也是不难的。