[GAP Forum] Problems with SetReducedMultiplication

[Josef Lauri]

I am defining a not too complicated finitely presented group as follows:

f:=FreeGroup(3);
rels:=[f.1^5,f.2^3,f.3^31,
       f.2*f.1*(f.1*f.2*f.3)^-1,
       f.3*f.1*(f.1*f.3^2)^-1,
       f.3*f.2*(f.2*f.3^25)^-1];
g:=f/rels;

I then want to express some products of the generators in reduced form. 
But even if I try

SetReducedMultiplication(g.1^5);
g.1^5;

which I hoped would give me the identity, gap just sits there for hours 
returning nothing. Same thing if I try


SetReducedMultiplication(g);

and then something like

g.2*g.1;

I'd be very grateful for some tips.

Josef Lauri