  Given a set E in a complex space and a point p in E, there is a unique
smallest complex-analytic germ containing the germ of E at p, called the
holomorphic closure of E at p. We study the holomorphic closure of
semialgebraic arc-symmetric sets. Our main application concerns CR-continuation
of semialgebraic arc-analytic mappings: A mapping f on a real-analytic CR
manifold M which is semialgebraic arc-analytic and CR on a non-empty open
subset of M is CR on the whole M.
