2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59181We put together some of the efforts by several people of making aspects of fibre bundle theory into algebra. The initiator of these efforts was Charles Ehresmann, who put the notion of groupoid and groupoid action in the focus of fibre bundle theory in general, and in connection theory in particular.13 pagesCategory TheoryDifferential Geometry18B40; 53B15text