Decision problems for HNN groups and vector addition systems
Michael Anshel · Mathematics of Computation · 1976
Our purpose is to show the equivalence of the conjugacy problem for certain HNN extensions of the infinite cyclic groups and the reachability problem for the class of self-dual vector addition systems. In addition, we extend an endomorphism theorem of the author’s to a homomorphism theorem and indicate a problem related to the isomorphism problem for a class of HNN groups.