  We consider the Lambek invariants (introduced by Joachim Lambek in 1964) in
the context of semiexact and homological categories in the sense of Grandis. We
generalize the Lambek isomorphism theorem to semiexact and homological
categories. Throughout the text, for completeness we give proofs of some lemmas
which are known in the additive case for the case of semiexact and homological
categories.

Category Theory