Definition 4.7.1.26. Let $(S, \leq )$ and $(T, \leq )$ be linearly ordered sets. We say that a function $f: S \rightarrow T$ is cofinal if it is nondecreasing and, for every element $t \in T$, there exists an element $s \in S$ satisfying $f(s) \geq t$.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$