The following seems relevant to Mac Lane's remark that he does not know of applications of universal algebra. In fact, in Computer Science, the line between UA and CATH is not so firmly drawn as in Mathematics, and there is actually a bias towards using the least sophisticated formalism possible for a given application. Joseph &&&&&&&&&&&&&&&&&&&&&&&&&&&&& Signature File &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Joseph A. Goguen, Professor of Computing Science, Programming Research Group, University of Oxford, 11 Keble Road, Oxford OX1 3QD, United Kingdom. email: Joseph.Goguen@prg.ox.ac.uk [internet] -- usually also works in the UK, but if not, try Joseph.Goguen@uk.ac.ox.prg phone: 272567 [my office]; 272568 [secy]; 273838 [PRG office]; 273839 or 272582 [FAX]. From USA, dial 011-44-865-...; from UK, dial (0865)-... ****************************************************************************** ******************************************************************************