Higher order derived functors and the Adams spectral sequence

Classical homological algebra studies chain complexes, resolutions, and derived functors in additive categories. In this paper we define higher order chain complexes, resolutions, and derived functors in the context of a new type of algebraic structure, called an algebra of left cubical balls. We show that higher order resolutions exist in these algebras, and that they determine higher order Ext-groups. In particular, the E_m-term of the Adams spectral sequence (m>2) is such a higher Ext-group, providing a new way of constructing its differentials.