Differential invariants of a Lie group action: Syzygies on a generating set

Given a group action, known by its infinitesimal generators, we exhibit a complete set of syzygies on a generating set of differential invariants. For that we elaborate on the reinterpretation of Cartan’s moving frame by Fels and Olver [Fels, M., Olver, P.J., 1999. Moving coframes. II. Regularization and theoretical foundations. Acta Appl. Math. 55 (2), 127–208]. This provides constructive tools for exploring algebras of differential invariants.