The cardinal successor of an ordinal $\alpha$, denoted by $\alpha^+$, is the least cardinal greater than $\alpha$.
The existence of $\alpha^+$ is justified by CARD > Proposition 3.
The cardinal successor of an ordinal $\alpha$, denoted by $\alpha^+$, is the least cardinal greater than $\alpha$.
The existence of $\alpha^+$ is justified by CARD > Proposition 3.