2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16217With the help of computer algebra, I devise an exact unitary transformation for the Anderson impurity model which allows to kill the hybridization term in the slightly simplified case of zero chemical potential. Then I compute explicitly the outcome of this transformation. This is a rigorous version of the well known Schrieffer-Wolff transformation. It should be possible to treat the general case at the price of increased computation time.33 pages, LaTeX2e using AMS symbolsStrongly Correlated Electronstext