Computing left Kan extensions

Abstract

We describe a new extension of the Todd-Coxeter algorithm adapted to computing left Kan extensions. The algorithm is a much simplified version of that introduced by Carmody and Walters (Category Theory, Proceedings of the International Conference Held in Como, Italy, 22-28 July 1990. Springer) in 1991. The simplification allows us to give a straightforward proof of its correctness and termination when the extension is finite. © 2003 Elsevier Science Ltd. All rights reserved.