Solution
= Solution
The <singular cardinals hypothesis> is the assertion that for every infinite <singular cardinal> $\kappa$,
$$
\boxed{2^{\operatorname{cf}(\kappa)}<\kappa
\quad\Longrightarrow\quad\kappa^{\operatorname{cf}(\kappa)}=\kappa^+.}
$$
In particular, for a singular strong-limit <cardinal> it gives $2^\kappa=\kappa^+$. This is a restriction on singular-cardinal exponentiation; it does not assert the full <Generalized continuum hypothesis> at all <cardinals>.