The Hanna Neumann conjecture is a statement about the rank of intersection two finitely generated subgroups free group. was posed by in 1957. In 2011, strengthened version proved independently Joel Friedman and Igor Mineyev. this paper we show that holds not only groups but also non-solvable surface groups. addition, retract group inert. This implies Dicks–Ventura inertia for

Fredrik Almqvist (a), Per Artursson (b), Hanna Axelsson (c), Marcus Carlsson (a) Inger Cullman (a), Mikael Elofsson (a), Per-Anders Enquist (a), Jonas Eriksson (a), Anders Esberg (a), Anna-Lena Gustavsson (c), Lars Hammarström (c), Martin Haraldsson (c), Annika Jenmalm Jensen* (c), Lars Johansson (c), Lucia Lazorova (b), Thomas Lundbäck (c), Maria Mastej (b), Weixing Qian (a), Kristmundur Sigmu...