| (i) | \begin{equation} X \neq \emptyset \end{equation} |
| ▼ | Set of symbols |
| ▼ | Alphabet |
| ▼ | Deduction system |
| ▼ | Theory |
| ▼ | Zermelo-Fraenkel set theory |
| ▼ | Set |
| ▼ | Binary cartesian set product |
| ▼ | Binary relation |
| ▼ | Map |
| ▼ | Cartesian product |
| ▼ | Set of maps |
| (i) | \begin{equation} X \neq \emptyset \end{equation} |