  A Fan-Theobald-von Neumann system is a triple $(V,W,\lambda)$, where $V$ and
$W$ are real inner product spaces and $\lambda:V\to W$ is a norm-preserving map
satisfying a Fan-Theobald-von Neumann type inequality together with a condition
for equality. Examples include Euclidean Jordan algebras, systems induced by
certain hyperbolic polynomials, and normal decomposition systems (Eaton
triples). The present article is a continuation of an earlier paper, where the
concepts of commutativity, automorphisms, majorization, and reduction were
introduced and elaborated. Here, we describe some transfer principles and
present Fenchel conjugate and subdifferential formulas.
