英语语法分析

A contravariant delegate can be assigned another delegate of the same type, but with a less derived generic type parameter.

可以向逆变委托分配同一类型的其他委托，但需使用派生程度较小的泛型类型参数。

The paper briefly explains the contravariant principle and the effect of the return of afterflow, suggests the method of rendering the return of afterflow.

简要地说明逆变原理及续流回路的作用，提出了绘制续流回路的方法。

A type can be declared contravariant in a generic interface or delegate if it is used only as a type of method arguments and not used as a method return type.

在泛型接口或委托中，如果类型形参仅用作方法返回类型，而不用于方法实参，则可声明为协变的。