Consider the Euclidean space Rn with the orthogonal action of a compact Lie group G.
We prove that a locally Lipschitz G-invariant mapping f from Rn to R can be uniformly approximated
by G-invariant smooth mappings g in such a way that the gradient of g is a graph approximation of
Clarke’s generalized gradient of f . This result enables a proper development of equivariant gradient
degree theory for a class of set-valued gradient...