  This short note contains random thoughts about a factorization theorem for
closure/interior operators on a powerset which is reminiscent to the notion of
resolution for a monad/comonad. The question originated from formal topology
but is interesting in itself. The result holds constructively (even if it
classically has several variations); but usually not predicatively (in the
sense that the interpolant will no be given by a set). For those not familiar
with predicativity issues, we look at a ``classical'' version where we bound
the size of the interpolant.
