Finally the guy sent them to me. To my utter astonishment, they are a published paper (http://www.numdam.org/item?id=PMIHES_1998__S88__23_0) already publicly available to download. The paper is by Pierre Cartier and has the amusing title "La folle journée, de Grothendieck à Connes et Kontsevich. Évolution des notions d’espace et de symétrie". The crazy journey of Grothendieck to Connes and Kontsevich. Evolution of the notions of space and symmetry. I see no reason to pursue this. Sorry to take up your time. Michael You're receiving this message because you're a member of the Categories mailing list group from Macquarie University. To take part in this conversation, reply all to this message. View group files<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMessage&action=files&smtp=categories%40mq.edu.au&bO=true&GuestId=6bf90c14-94d1-45b7-a0b5-9dd447734d27> | Leave group<https://outlook.office365.com/groups/groupsubscription?source=EscalatedMessage&action=leave&smtp=categories%40mq.edu.au&bO=true&GuestId=6bf90c14-94d1-45b7-a0b5-9dd447734d27> | Learn more about Microsoft 365 Groups<https://aka.ms/o365g>