= Stationary partition by cofinal-sequence fibers
{title2=$\kappa=\bigsqcup_{\xi<\kappa}S_\xi$}
For an uncountable <regular cardinal> $\kappa$, choose cofinal sequences $c_\alpha:\omega\to\alpha$ for the <stationary set> of <ordinals> of <cofinality> $\omega$. Above any bound, some fixed coordinate exceeds the bound on a stationary <subset>; <Fodor lemma> makes that coordinate constant on a stationary <subset>. Thus the stationary constant fibers, over all coordinates, have unboundedly many values. Regularity makes one coordinate have $\kappa$ such values. Its fibers are disjoint <stationary sets>; adding all leftover <ordinals> to one piece partitions $\kappa$.
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