2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68940We construct a finitely presented group with coNP-complete word problem, and a finitely generated simple group with coNP-complete word problem. These groups are represented as Thompson groups, hence as partial transformation groups of strings. The proof provides a simulation of combinational circuits by elements of the Thompson-Higman group G_{3,1}.73 pagesGroup Theory20F10, 68Q15text