2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/71164We show that the Hardy-Littlewood maximal operator and a class of Calderón-Zygmund singular integrals satisfy the strong type modular inequality in variable $L^p$ spaces if and only if the variable exponent $p(x)\sim const$.Classical Analysis and ODEs42B20; 42B25text