2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/70568We consider the matrix ${\frak Z}_P=Z_P+Z_P^t$, where the entries of $Z_P$ are the values of the zeta function of the finite poset $P$. We give a combinatorial interpretation of the determinant of ${\frak Z}_P$ and establish a recursive formula for this determinant in the case in which $P$ is a boolean algebra.14 pages, AMS-TeXCombinatorics05C20,05C50,06A11,15A15text