All-order Feynman rule for leading-twist quark operators

We present an expression for the Feynman rule for leading-twist quark operators with an arbitrary number of total derivatives and an arbitrary number of gluons. This provides a generalization of known results and constitutes a necessary ingredient in the computation of the matrix elements of the corresponding operators. The result is in a form appropriate for implementation in a computer algebra system. To illustrate the latter we provide implementations in Mathematica and FORM, which are made available at https://github.com/vtsam/NKLO.