Word problem for a group (source code)

= Word problem for a group
{wiki=Word_problem_for_groups}

= Word problem for groups
{synonym}

For a fixed finitely generated <group> with specified generators, its word problem asks for an algorithm deciding whether an input word represents the identity. For a finitely presented group, positive answers can be enumerated from the relators, but there need not be an algorithm deciding both positive and negative answers. An effective reduction from a nonrecursive <halting set> proves unsolvability.