2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/54383The topological twist of N=2, D=4 matter-coupled supergravities requires a suitable R-symmetry. This symmetry is realised in the effective supergravities arising at tree level from certain heterotic compactifications. The set of instanton equations (topological gauge-fixings) is thus obtained. The conditions that R-symmetry should satisfy also when these theories are replaced by their ``exact'' quantum-corrected counterparts are investigated.11 pages, plain LaTex. To Appear in the Proceedings of the conference ``Gauge theories, applied supersymmetry and quantum gravity'', Leuven, July 1995High Energy Physics - Theorytext