A D11: Set $E$ is a proper subset of $X$ if and only if
| (1) | $\forall \, x \in E : x \in X$ | (D78: Subset) |
| (2) | $E \neq X$ |
| ▼ | Set of symbols |
| ▼ | Alphabet |
| ▼ | Deduction system |
| ▼ | Theory |
| ▼ | Zermelo-Fraenkel set theory |
| ▼ | Set |
| ▼ | Subset |
| (1) | $\forall \, x \in E : x \in X$ | (D78: Subset) |
| (2) | $E \neq X$ |
| ▶ |
Convention 0
(Notation for proper subset relation)
If $X$ is a D11: Set and $E$ is a D101: Proper subset of $X$, we denote this by $E \subset X$.
|