A non-separable Christensen's theorem and set tri-quotient maps

S. Nedev, J. Pelant, V. Valov

For every space $X$ let $\mathcal{K}(X)$ be the set of all compact subsets of $X$. Christensen \cite{c:74} proved that if $X,Y$ are separable metrizable spaces and $F\colon\mathcal…