  We give a description of Hausdorff continuous open images of the Sorgenfrey
line: these are precisely those spaces that have a Sorgenfrey base. Using this
description we prove that no Hausdorff compact space that contains a copy of
the Sorgenfrey line is a continuous open image of it; in particular the
double-arrow space is not a continuous open image of the Sorgenfrey line.
