Corollary 4.7.1.15 (Rigidity). Let $(S, \leq )$ and $(T, \leq )$ be linearly ordered sets, and let $f,f': S \hookrightarrow T$ be initial segment embeddings. If $S$ is well-ordered, then $f = f'$.
$\Newextarrow{\xhookrightarrow}{10,10}{0x21AA}$
Corollary 4.7.1.15 (Rigidity). Let $(S, \leq )$ and $(T, \leq )$ be linearly ordered sets, and let $f,f': S \hookrightarrow T$ be initial segment embeddings. If $S$ is well-ordered, then $f = f'$.