2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/226847If the preimage of a four-point set under a meromorphic function belongs to the real line, then the image of the real line is contained in a circle in the Riemann sphere. We include an application of this result to holomorphic dynamics: if the Julia set of a rational function is contained in a smooth curve then it is contained in a circle.6 pagesComplex VariablesDynamical Systems37F10, 30D05, 30D30text