2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/211020To avoid problems with infinite measure, the functional integral for harmonic oscillator can be calculated by time - slicing method with continuum limit procedure proposed Gelfand and Yaglom. In previous article we proved by nonperturbative calculation the generalized Gelfand-Yaglom equation for anharmonic oscillator with positive or negative mass term. In this article we prove by step-by-step the calculation of the correction function to the Gelfand-Yaglom equation for an-harmonic oscillator.New proof of the formulas added, text claryfiedHigh Energy Physics - Theorytext