  We prove semi-rationalification and semi-log-canonicalization for Gorenstein
demi-normal surfaces. That is, given a Gorenstein demi-normal surface X with
semi-rational (respectively, semi-log canonical) singularities in an open set U
with complement a finite set of points, there is a proper birational morphism f
: Y --> X such that f is an isomorphism over U and Y has only semi-rational
(respectively, semi-log canonical) singularities. We proceed by passing to the
normalization and then gluing along the conductor in an appropriate
rationalification or log-canonicalization of the normalization of X.

Algebraic Geometry