Using the theory of minimal models of quasi-projective surfaces we give a new
proof of the theorem of Lin-Zaidenberg which says that every topologically
contractible algebraic curve in the complex affine plane has equation Xn=Ym
in some algebraic coordinates on the plane. This gives also a proof of the
theorem of Abhyankar-Moh-Suzuki concerning embeddings of the complex line into
the plane. Independently, we show how to deduce the latter theorem from basic
properties of Q-acyclic surfaces.Comment: 12 pages, 1 figur