a}[a_{\alpha}{\mathord{\upharpoonright}}\xi_\alpha]$.  $\square$  A set $A\subseteq {{\mathfrak{K}}}^\kappa$ is ${\boldsymbol{\text{S}{{\mathcal{N}}}}}_\kappa$ if and only if there exists $\lambda<\kappa$ such that $A$ is $\lambda$-$