Recalling that a C-infty algebra is a copresheaf which becomes a copresheaf with values in algebras when restricted along , the idea is to define a smooth module over a C-infinity algebra to be a copresheaf which becomes a copresheaf of modules over the copresheaf of algebras when restricted along .
Definition
A -module over a C-infinity algebra is a co-presheaf such that restricted along it becomes a copresheaf of modules over the copresheaf (on ) of algebras .