A note on *orthant-monotonic norms Original Research Article

Let K be the field of real or complex numbers. A characterization of *orthant-monotonicity of a norm on Kn by its subdifferential is given, and applied to obtain a description of all inner product norms p1, p2 on Kn for which certain composite norms xmaps tog(p1(x),p2(x)) on Kn are *orthant-monotonic.