Giné Mesa, JaumeGrau Montaña, Maite2016-02-182016-02-182007-09Giné Mesa, J. y Grau Montaña, M. (2007). Weierstrass integrability of differential equations.http://hdl.handle.net/11441/35074The integrability problem consists in finding the class of functions a first integral of a given system must belong to. We recall the characterization to admit an elementary or Liouvillian first integral. We define Weierstrass integrability and we determine which Weierstrass integrable systems are Liouvillian integrable. Inside this new class of integrable systems there are non–Liouvillian integrable systems.application/pdfengAttribution-NonCommercial-NoDerivatives 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/nonlinear differential equationsintegrability probleminfo:eu-repo/semantics/conferenceObjectinfo:eu-repo/semantics/openAccess