Issue no. 1 Table of Contents

A constructive “Closed subgroup theorem” for localic groups and groupoids
Peculiar behavior of connected locales
Remarks on duality for Σ-groups. I. Products and coproducts
A model structure for the homotopy theory of crossed complexes
On the connectedness of some topological spaces

Issue no. 2 Table of Contents

Multiplicative lattices and C * -algebras
Finitary fibrations
Completions of categories and initial completions
The relation between homotopy limits and Bauer's shape singular complex
On primeness and maximality of filters

Issue no. 3 Table of Contents

Approximation axiomatique à la théorie du bordisme
Topological quasitopos hulls of categories containing topological and metric objects
Morphisms between spaces of leaves viewed as fractions
Functionally Hausdorff spaces
Comparaison de deux catégories d'homotopie de morphismes cohérents

Issue no. 4 Table of Contents

L'unité de la théorie des modèles et de l'algèbre homologique
Non-abelian cohomology of associative algebras. The 9-term exact sequence
An exterior product for the homology of groups with integral coefficients modulo p
Onto Gelfand maps : appendix
The natural number bialgebra