2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73863We show that several classical bilateral summation and transformation formulas have semi-finite forms. We obtain these semi-finite forms from unilateral summation and transformation formulas. Our method can be applied to derive Ramanujan's $_1ψ_1$ summation, Bailey's $_2ψ_2$ transformations, and Bailey's $_6ψ_6$ summation.8 pages. accepted by Proc. Amer. Math. SocClassical Analysis and ODEsCombinatorics33D15, 05A30Semi-Finite Forms of Bilateral Basic Hypergeometric Seriestext