2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/184585A class of differential calculi is explored which is determined by a set of automorphisms of the underlying associative algebra. Several examples are presented. In particular, differential calculi on the quantum plane, the $h$-deformed plane and the quantum group GLpq(2) are recovered in this way. Geometric structures like metrics and compatible linear connections are introduced.28 pages, some references added, several amendments of minor importance, remark on modular group in section 8 omitted, to appear in J. Phys. AMathematical PhysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Theorytext