2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/96981Every o-minimal expansion R-tilde of the real field has an o-minimal expansion P(R-tilde) in which the solutions to Pfaffian equations with definable C^1 coefficients are definable.Rings and AlgebrasThe Pfaffian closure on an o-minimal structuretext