2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/136496We give a generalization of Yamaguchi--Yau's result to Walcher's extended holomorphic anomaly equation.19 pages, 3 figures, (v2) a reference addedAlgebraic GeometryHigh Energy Physics - Theory14J32 (Primary); 14N35, 14J81 (Secondary)text