2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/30662We show that there is a query expressible in first-order logic over the reals that returns, on any given semi-algebraic set A, for every point a radius around which A is conical. We obtain this result by combining famous results from calculus and real algebraic geometry, notably Sard's theorem and Thom's first isotopy lemma, with recent algorithmic results by Rannou.9 pagesDatabasesLogic in Computer ScienceH.2.3; H.2.8text