Cardinal Number Definition

Cardinal Number Sentence Examples

• Two classes between which a one-one relation exists have the same cardinal number and are called cardinally similar; and the cardinal number of the class a is a certain class whose members are themselves classes - namely, it is the class composed of all those classes for which a one-one correlation with a exists.

• Thus the cardinal number of a is itself a class, and furthermore a is a member of it.

• Thus the cardinal number one is the class of unit classes, the cardinal number two is the class of doublets, and so on.

• The cardinal number zero is the class of classes with no members; but there is only one such class, namely - the null class.

• Zero is a cardinal number.