2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213502Sufficient boundary asymptotic conditions are established for a generalized Schur function $f$ to be identically equal to a given rational function $g$ unimodular on the unit circle. Similar rigidity statements are presented for generalized Carathéodory and generalized Nevanlinna functions.Classical Analysis and ODEsComplex Variables47A57text