Gimel function
= Gimel function
{title2=$\gimel(\kappa)=\kappa^{\operatorname{cf}(\kappa)}$}
For an infinite <cardinal number>, $\gimel(\kappa)=\kappa^{\operatorname{cf}(\kappa)}$. The <singular cardinals hypothesis> predicts its value when $\kappa$ is a <singular cardinal> and $2^{\operatorname{cf}(\kappa)}<\kappa$. For a <regular cardinal>, its value is $2^\kappa$.