  In recent papers it has been noted that the local potential approximation of
the Legendre and Wilson-Polchinski flow equations give, within numerical error,
identical results for a range of exponents and Wilson-Fisher fixed points in
three dimensions, providing a certain ``optimised'' cutoff is used for the
Legendre flow equation. Here we point out that this is a consequence of an
exact map between the two equations, which is nothing other than the exact
reduction of the functional map that exists between the two exact
renormalization groups. We note also that the optimised cutoff does not allow a
derivative expansion beyond second order.
