Thomas Ehrhard
MSCS - Mathematical Structures in Computer Science, 2:365--385,
1993
Slightly changed version
Available as PostScript, DVI.
Comments:
ISSN: 0960-1295
Authors address: Laboratoire
de Math'ematiques Discrètes, UPR 9016 du CNRS, 163 avenue de Luminy,
case 930, F 13288 MARSEILLE CEDEX 9. ehrhard@lmd.univ-mrs.fr.