  Let A be an idempotent algebra on a 3-element domain D that omits a G-set for
a factor. Suppose A is not \alpha\beta-projective (for some alpha, beta subsets
of D) and is not collapsible. It follows that A is switchable. We prove that,
for every finite subset Delta of Inv(A), Pol(Delta) is collapsible. We also
exhibit an algebra that is collapsible from a non-singleton source but is not
collapsible from any singleton source.
