RT journal article T1 C∞-structures in the integration of involutive distributions A1 Pan Collantes, Antonio Jesús A1 Ruiz Serván, Adrián A1 Muriel Patino, María Concepción A1 Romero Romero, Juan Luis A2 Matemáticas K1 symmetry of a distribution K1 solvable structure K1 C∞-symmetry of a distribution K1 C∞-structure K1 integrating factor K1 differential equations AB For a system of ordinary differential equations (ODEs) or, more generally, an involutive distribution of vector fields, the problem of its integration is considered. Among the many approaches to this problem, solvable structures provide a systematic procedure of integration via Pfaffian equations that are integrable by quadratures. In this paper structures more general than solvable structures (named C∞-structures) are considered. The symmetry condition in the concept of solvable structure is weakened for C∞-structures by requiring their vector fields be just C∞-symmetries. For C∞structures there is also an integration procedure, but the corresponding Pfaffian equations, although completely integrable, are not necessarily integrable by quadratures. The well-known result on the relationship between integrating factors and Lie point symmetries for first-order ODEs is generalized for C∞-structures and involutive distributions of arbitrary corank by introducing symmetrizing factors. The role of these symmetrizing factors on the integrability by quadratures of the Pfaffian equations associated with the C∞-structure is also established. Some examples that show how these objects and results can be applied in practice are also presented. SN 1402-4896 YR 2023 FD 2023-05-12 LK http://hdl.handle.net/10498/32130 UL http://hdl.handle.net/10498/32130 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 10-may-2026