2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73323In analogy with the classical group law on a plane cubic curve, we define a group law on a smooth plane tropical cubic curve. We show that the resulting group is isomorphic to $S^1$.13 pages, latex2e, 5 figures as pstex and pstex_t filesAlgebraic GeometryCombinatoricstext