(i) | \begin{equation} X \neq \emptyset \end{equation} |
(ii) | ${\sim} \subseteq X \times X$ is an D178: Equivalence relation on $X$ |
(i) | \begin{equation} X \neq \emptyset \end{equation} |
(ii) | ${\sim} \subseteq X \times X$ is an D178: Equivalence relation on $X$ |