[GAP Forum] Join of two subgroups (as FP groups)

[William Giuliano]

Dear Forum,
                     suppose I have two subgroups H1 and H2 of a (matrix)
group G, such that their join is the whole of G. When I convert H1 and H2
into Fp groups, and consider the quotient of the free group on the union of
their generators by the union of their relations, how should the resulting
Fp group be considered in GAP?

Thank you very much
William