2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/113921Counter automata are more powerful versions of finite-state automata where addition and subtraction operations are permitted on a set of n integer registers, called counters. We show that the word problem of $\Z^n$ is accepted by a nondeterministic $m$-counter automaton if and only if $m \geq n$.8 pagesGroup Theory20F10, 68Q45text