2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/44887By using the example of photon-photon scattering box diagrams, different representations for loop integrals are discussed. A connection between hypergeometric representation and dilogarithms is derived. An explicit analytic continuation formula to large values of Mandelstam variables is constructed.8 pages, to appear in: Proc. Intern. Conf. "Quarks-92" (Zvenigorod, Russia, May 1992), World Scientific, Singapore, 1993High Energy Physics - Phenomenologytext