Axiom one: all group operations must be closed or restricted to only group elements.

公理一：所有群操作必须是封闭的或仅限于群元素。

Axiom two: no matter where we put parentheses when we're doing a single group operation, we still get the same result.

公理二：无论我们在进行单个组运算时将括号放在何处，我们仍然会得到相同的结果。

The United States has imposed sanctions on a Russian man Ivan Maslov who it says is the leader of the Wagner mercenary groups operation in Mali.

美国制裁了一名俄罗斯男子伊万·马斯洛夫，美国称他是瓦格纳雇佣军组织在马里的头目。

When the two are brought together using the group's addition operation, they result in the identity element, zero, so they can be thought of as cancelling each other out.

当使用群的加法运算将两者放在一起时，它们的单位元为零，因此可以认为它们相互抵消了。