A D11: Set $\mathcal{C} \subseteq \mathcal{P}(X)$ is a closed cover for $X$ with respect to $T$ if and only if
| (1) | $X \subseteq \cup \mathcal{C}$ (D74: Set cover) |
| (2) | $\forall \, E \in \mathcal{C} : X \setminus E \in \mathcal{T}$ |
| ▼ | Set of symbols |
| ▼ | Alphabet |
| ▼ | Deduction system |
| ▼ | Theory |
| ▼ | Zermelo-Fraenkel set theory |
| ▼ | Set |
| ▼ | Collection of sets |
| ▼ | Set union |
| ▼ | Set cover |
| ▼ | Open set cover |
| (1) | $X \subseteq \cup \mathcal{C}$ (D74: Set cover) |
| (2) | $\forall \, E \in \mathcal{C} : X \setminus E \in \mathcal{T}$ |