  We apply population synthesis techniques to calculate the present day number
of two types of white dwarf-main sequence star (WDMS) binaries within the
cataclysmic variable period gap. The first are post-common envelope binaries
with secondary stars that have masses between 0.17 and 0.36 Msun (gPCEBs), such
that they will commence mass transfer within the period gap. The second type
are systems that were CVs at some point in their past, but detached once they
evolved down in orbital period to ~3 h as a consequence of disrupted magnetic
braking, and are crossing the period gap via gravitational radiation (dCVs).
Full population synthesis calculations are performed where we assume either
constant, global values of the common envelope ejection efficiency, or consider
the ejection efficiency as a function of secondary mass. Several forms of
magnetic braking are also considered. We predict an excess of dCVs over gPCEBs
within the period gap of ~4 to ~13 assuming an ejection efficiency between 0.1
and 0.6, and a flat initial mass ratio distribution. This excess is revealed as
a prominent peak at the location of the period gap in the orbital period
distribution of the combined gPCEB and dCV population. We suggest that if such
a feature is observed in the orbital period distribution of an observed sample
of short orbital period WDMS binaries, this would strongly corroborate the
disruption of magnetic braking.
