A typical kind of property that you might want to express, say, in a class invariant for a graph class, is that the graph has no cycles.

比如在一个图类中，你可能想要表述的典型属性是该图没有回路。这就是一个一阶谓词演算不可表述的属性。

youdao

A typical kind of property that you might want to express, say, in a class invariant for a graph class, is that the graph has no cycles.

比如在一个图类中，你可能想要表述的典型属性是该图没有回路。这就是一个一阶谓词演算不可表述的属性。

youdao