2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/39178We discuss a number of old and new methods for computing $K\toππ$ amplitudes on the lattice. They all involve a non-perturbative determination of matching coefficients. We show how problems related to operator mixing can be greatly reduced by using point-split hadronic currents.7 pages, plain Latex. Talk given at "Cortona 1998", Cortona - ItalyHigh Energy Physics - Latticetext