GAP 4.8.9 installation with standard packages -- copy to your CoCalc project to get it
gap> START_TEST("HAP library"); gap> x:=(1,2)(5,6)(7,8)(11,12);; y:=(2,3)(4,5)(8,9)(10,11);; gap> z:=(3,4)(5,7)(6,8)(9,10);; G:=Group(x,y,z);; gap> CayleyGraphOfGroupDisplay(G,[x,y,z]); gap> Y:=EquivariantTwoComplex(G); Equivariant CW-complex of dimension 2 gap> F:=FundamentalGroupOfQuotient(Y); <fp group on the generators [ f1, f2, f3 ]> gap> RelatorsOfFpGroup(F); [ f1^2, f2^2, f3^2, f1*f3*f1^-1*f3^-1, f3*f2*f3*f2^-1*f3^-1*f2^-1, (f2*f1)^2*f2*(f1^-1*f2^-1)^2*f1^-1 ] gap> H:=Group(x*y,x*z,y*z);; gap> W:=RestrictedEquivariantCWComplex(Y,H); Equivariant CW-complex of dimension 2 gap> FH:=FundamentalGroupOfQuotient(W); <fp group on the generators [ f1, f2, f3, f4, f5 ]> gap> RelatorsOfFpGroup(FH); [ f1, f1, f3*f2, f2*f3, f5*f4, f4*f5, f1*f4*f5^-1, f5*f1^-1*f4^-1, f4*f3*f4*f2^-1*f5^-1*f2^-1, f5*f2*f5*f3^-1*f4^-1*f3^-1, (f2*f1)^2*f2*f3^-2, f3^3*(f1^-1*f2^-1)^2*f1^-1 ] gap> xz:=(1,2)(3,4)(5,8)(6,7)(9,10)(11,12);; gap> yz:=(2,4,7,5,3)(6,8,10,11,9);; gap> H:=Group(xz, yz);; gap> W:=EquivariantTwoComplex(H); Equivariant CW-complex of dimension 2 gap> FH:=FundamentalGroupOfQuotient(W); <fp group on the generators [ f1, f2 ]> gap> RelatorsOfFpGroup(FH); [ f2^2, f1^5, (f1*f2)^2*f1*f2^-1 ] gap> STOP_TEST( "tst.tst", 1000 );