The method proposed by Pratt to derive recursion relations for systems of
degenerate fermions [Phys. Rev. Lett. 84, 4255 (2000), arXiv:nucl-th/9905055]
relies on diagrammatic techniques. This efficient formalism assumes no explicit
two-body interactions, makes possible the inclusion of conservation laws and
requires low computational time. In this brief report, we show that such
recursion relations can be obtained from generating functions, without any
restriction as concerns the number of conservation laws (e.g. total energy or
angular momentum).Comment: submitted to Physical Review