Test elements for monomorphisms of free lie algebras and lie superalgebras^†

Abstract

A test criterion for an endomorphism φ of the free Lie (super) algebra L of finite rank to be an automorphism is obtained: φ is an automorphism of L if and only if for an element u ∈ L with the maximal rank the element φ(u) belongs to the orbit of u with respect to the automorphism group of L. In particular, test elements for monomorphisms of L are exactly the elements of the maximal rank