An D548: Ordered pair $G_E = (E, \mathcal{E}_E)$ is a subdigraph of $G_X$ if and only if
(1) | $E \subseteq X$ | (D78: Subset) |
(2) | $\mathcal{E}_E \subseteq \mathcal{E}_X$ | (D78: Subset) |
(1) | $E \subseteq X$ | (D78: Subset) |
(2) | $\mathcal{E}_E \subseteq \mathcal{E}_X$ | (D78: Subset) |