Suppose \(\coprod_{\alpha\in A} X_\alpha\) is a disjoint union space . For each \(\alpha\in A\) the canonical injection \(\iota_\alpha\colon X_\alpha\to \coprod_{\alpha\in A} X_\alpha\) is given by \(\iota_\alpha(x)=(x,\alpha)\).
Suppose \(\coprod_{\alpha\in A} X_\alpha\) is a disjoint union space . For each \(\alpha\in A\) the canonical injection \(\iota_\alpha\colon X_\alpha\to \coprod_{\alpha\in A} X_\alpha\) is given by \(\iota_\alpha(x)=(x,\alpha)\).