2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/6558A formula to investigate wave effect in multi-lens system is presented on the basis of path integral formalism by generalizing the work by Nakamura and Deguchi (1999). Wave effect of a system with two lenses is investigated in an analytic way as a simple application to demonstrate usefulness of the formula and variety of wave effect in multi-lens system.5 pages, 4 figuresAstrophysicstext