2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/76947It has been proved several times in the literature that a polynomial map from $C^2$ to $C$ with irreducible rational fibers cannot be a component of a counterexample to the Jacobian Conjecture. This note points out that this result is empty: it is implicit in 1980 work of Miyanish and Sugie that such a polynomial is equivalent to $f(x,y)=x$ by a polynomial automorphism of $C^2$.1 1/2 pagesAlgebraic Geometrytext