_LR := rec < recformat< F: GrpFP, AI: SeqEnum, G: GrpMat > |
      F := FreeGroup(2) >;
_LR`AI := [ [a, a*b*b*a*b*a*b*b] ] where a is (_LR`F).1 where b is (_LR`F).2;
//two consitutents interchanged by _LR`AI[1]

_LR`G := sub<GL(4,Integers()) |
\[ 0,1,0,0,1,0,0,0,0,0,0,1,0,0,1,0 ],
\[ -1,0,1,0,-1,1,0,0,-1,0,0,0,-1,0,0,1 ] >;

return _LR;
