Let $\mathcal{C}$ be a D74: Set cover for $X$.
A D11: Set $\mathcal{S}$ is a subcover of $\mathcal{C}$ for $X$ if and only if
(1) | $X \subseteq \cup \mathcal{S}$ (D74: Set cover) |
(2) | $\mathcal{S} \subseteq \mathcal{C}$ (D78: Subset) |
(1) | $X \subseteq \cup \mathcal{S}$ (D74: Set cover) |
(2) | $\mathcal{S} \subseteq \mathcal{C}$ (D78: Subset) |