GROUPS, GRAPHS, AND THE HANNA NEUMANN CONJECTURE
Igor Mineyev · Journal of Topology and Analysis · 2012
Submultiplicativity, an analytic property generalizing the Strengthened Hanna Neumann Conjecture (SHNC) to complexes was proved in [2] assuming the deep-fall property. This in particular implied SHNC. The purpose of this note is to write the proof of the original SHNC and purely in terms of groups and graphs. We also give explicit examples showing that the upper bound in SHNC is sharp.