Type: Article
Publication Date: 2000-08-09
Citations: 39
DOI: https://doi.org/10.2140/gt.2000.4.179
We prove algebraic analogues of the facts that a curve on a surface with selfintersection number zero is homotopic to a cover of a simple curve, and that two simple curves on a surface with intersection number zero can be isotoped to be disjoint.