Algorithmic aspects of branched coverings III/V. Erasing maps, orbispaces, and the Birman exact sequence

Laurent Bartholdi, Dzmitry Dudko

Let $\tilde{f}:(S^2,\tilde{A})\to (S^2,\tilde{A})$ be a Thurston map and let $M(\tilde{f})$ be its mapping class biset: isotopy classes rel $\tilde{A}$ of maps obtained by pre- and…