  The relation between the trace and R-current anomalies in 4D supersymmetric
theories implies that the U(1)$_R$F$^2$, U(1)$_R$ and U(1)$^3_R$ anomalies
which matched in studies of N=1 Seiberg duality satisfy positivity constraints.
These constraints are tested in a large number of N=1 supersymmetric gauge
theories in the non-Abelian Coulomb phase, and they are satisfied in all
renormalizable models with unique anomaly-free R-current, including those with
accidental symmetry. Most striking is the fact that the flow of the Euler
anomaly coefficient, $a_{UV}-a_{IR}$, is always positive, as conjectured by
Cardy.
