  We use recent results of Intriligator and Wecht [hep-th/0304128] to study the
phase structure of $\NN=1$ super Yang-Mills theory with gauge group $SU(N_c)$,
a chiral superfield in the adjoint, and $N_f$ chiral superfields in the
fundamental representation of the gauge group. Our discussion sheds new light
on [hep-th/0304128] and supports the conjecture that the central charge $a$
decreases under RG flows and is non-negative in unitary four dimensional
conformal field theories.
