Fermionic sign cancellations in the continuous renormalization group equation

I derive a Wick-ordered continuous renormalization group equation for fermions and show a determinant bound for the solution. This reduces the combinatorial factor in the recursion for fermionic theories by a factorial, as compared to bosons, and thus suggests that convergence of perturbation theory can be proven in the absence of couplings that grow under the renormalization flow.