Issue no. 1 Table of Contents

International category theory meeting. Bangor, Wales, july 2-7 1989. Cambridge, England, march 23-25, 1990
p. 3
More on graphic toposes
p. 5-10
Combinatorial-geometric aspects of polycategory theory : pasting schemes and higher Bruhat orders (list of results)
p. 11-27
∞-groupoids and homotopy types
p. 29-46
A 2-categorical approach to change of base and geometric morphisms I
p. 47-95

Issue no. 2 Table of Contents

The frame of fibrewise closed nuclei
p. 99-112
The exact sequence in the homology of groups with integral coefficients modulo q associated to two normal subgroups
p. 113-129
Almost smooth algebras
p. 131-138
Monads and cocompleteness of categories
p. 139-144
Presentations of étendues
p. 145-164
Indexed categories for program development
p. 165-185

Issue no. 3 Table of Contents

What is a double central extension ? (the question was asked by Ronald Brown)
p. 191-201
The connection between the fundamental groupoid and a unification algorithm for syntactil algebras (extended abstract)
p. 203-242
On Priestley duals of products
p. 243-256
Strong regular and dense generators
p. 257-276

Issue no. 4 Table of Contents

Catégorie algébriques prégaloisiennes
p. 279-296
ϰ-Lindelöf locales and their spatial parts
p. 297-313
Parity complexes
p. 315-343
Counting measure for Kuratowski finite parts and decidability
p. 345-353