L. A. Lambe, W. M. Seiler
abstract:
We propose a new point of view of the Spencer cohomology appearing in the 
formal theory of differential equations based on a dual approach via comodules. 
It allows us to relate the Spencer cohomology with standard constructions in 
homological algebra and, in particular, to express it as a Cotor. We discuss 
concrete methods for its construction based on homological perturbation theory.