Dear Gap Forum

I defined the group g generated by matrices
gap> x:=[ [ 0, 0, 0, 0, 0, 1, 0 ], [ 0, 0, 0, 0, 0, 0, 1 ],
          [ 1, 0, 0, 0, 0, 0, 0 ], [ 0, 1, 0, 0, 0, 0, 0 ],
          [ 0, 0, 1, 0, 0, 0, 0 ], [ 0, 0, 0, 1, 0, 0, 0 ],
          [ 0, 0, 0, 0, 1, 0, 0 ] ];

and

gap> y:= [ [ 1, 0, 0, 0, 0, 0, 0 ],
           [ 2/3, -1/3, 2/3, -1/3, -1/3, -1/3, -1/3 ],
           [ 2/3, -1/3, -1/3, -1/3, 2/3, -1/3, -1/3 ],
           [ 1/3, 1/3, 1/3, -2/3, 1/3, 1/3, -2/3 ],
           [ 2/3, 2/3, -1/3, -1/3, -1/3, -1/3, -1/3 ],
           [ 1/3, 1/3, 1/3, -2/3, 1/3, -2/3, 1/3 ],
           [ 1/3, 1/3, 1/3, 1/3, 1/3, -2/3, -2/3 ] ] ;

and tried to find the

gap> InvariantBilinearForm(g);

But I got:

Error, no method found! For debugging hints type ?Recovery from
NoMethodFound
Error, no 2nd choice method found for `InvariantBilinearForm' on 1
arguments c\
alled from
<function>( <arguments> ) called from read-eval-loop
Entering break read-eval-print loop ...
you can 'quit;' to quit to outer loop, or
you can 'return;' to continue

I appreciate you let me know my problem.

Regards, Vahid Dabbaghian