that the blood group is not AB- without revealing the blood group.
In both these examples, the city and blood group were attributes of a credential and the holder convinced some facts about those without revealing them.
在不透露血型的情况下，血型不是AB-。
在这两个例子中，城市和血型都是证书的属性，持有者在没有透露的情况下说服了这些人的一些事实。