Can anyone help me with accessible (in both senses of the word) references to algebraic (as in many-sorted algebraic specifications) or category theoretic definitions of linear algebra (real numbers, vector space, Banach space, Hilbert space, tensors, manifolds, etc.). Most books on linear algebra do this to some extent, but, after establishing the isomorphism between matrices and homomorphisms over vector spaces, the rest of the exposition is done in terms of the matrix representation. This is especially true for the area of tensors, which has developed its own peculiar notation. Magne Magne Haveraaen e-mail: magne@ii.uib.no Dept. of Informatics phone: +47 (5) 544154 University of Bergen fax: +47 (5) 544199 Hoyteknologisenteret N-5020 BERGEN Norway ==============================================================================