  This article provides a version of scale calculus geared towards a notion of
(nonlinear) Fredholm maps between certain types of Frechet spaces, retaining as
many as possible of the properties Fredholm maps between Banach spaces enjoy,
and the existence of a constant rank theorem for such maps. It does so by
extending the notion of linear Fredholm maps from [HWZ14] and [Weh12] to a
setting where the Nash-Moser inverse function theorem can be applied and which
also encompasses the necessary examples such as the reparametrisation action
and (nonlinear) elliptic partial differential operators.
