Before revision:  We implement the re-weighting as an inner product in a function space called a reproducing kernel Hilbert space (RKHS), with a  closed form solution that can be computed in one line of code.
After revision:  We implement the re-weighting as an inner product in a function space called a reproducing kernel Hilbert space (RKHS), with a one line, closed form solution that can be computed in one line of code.