gap> K3:=SimplicialK3Surface();
Simplicial complex of dimension 4.

gap> f:=IntersectionForm(K3);;
gap> Display(f);
[ [   54,  -14,    0,   -1,    4,   -5,    6,  -10,    2,    1,   -2,    2,   -1,    3,    5,   -1,    1,   -2,   -4,    4,    8,    4 ],
  [  -14,    4,    1,    2,   -4,    3,   -4,    6,   -1,    2,    2,   -1,    1,    2,   -4,   -1,    3,    2,    0,   -1,   -5,   -4 ],
  [    0,    1,    2,    1,    0,   -2,    1,   -1,   -2,    0,    1,   -1,    1,   -1,    1,    1,    0,    1,    0,    0,    0,    1 ],
  [   -1,    2,    1,    2,   -1,   -1,    1,    1,   -4,    0,    2,   -1,    2,    0,    1,    0,    1,    1,    0,   -1,   -1,    1 ],
  [    4,   -4,    0,   -1,    2,   -1,    0,   -1,    2,   -1,    0,    1,    0,    0,    1,    0,    0,    0,    0,    0,    1,    0 ],
  [   -5,    3,   -2,   -1,   -1,    4,   -2,    1,    2,    1,   -2,    0,   -2,    0,   -3,    0,   -1,   -1,    0,    0,    0,   -2 ],
  [    6,   -4,    1,    1,    0,   -2,    2,    0,   -1,    0,    1,    0,    1,    1,    1,    0,    1,    1,   -1,    0,    0,    1 ],
  [  -10,    6,   -1,    1,   -1,    1,    0,    4,   -5,    0,    1,   -1,    1,    0,   -1,    0,    0,    1,    1,   -1,   -2,    0 ],
  [    2,   -1,   -2,   -4,    2,    2,   -1,   -5,   10,    1,   -4,    0,   -3,   -2,   -1,    0,   -3,   -4,   -1,    2,    3,   -1 ],
  [    1,    2,    0,    0,   -1,    1,    0,    0,    1,    2,   -1,   -1,   -1,    1,   -2,    0,    0,    0,   -1,    1,    0,   -1 ],
  [   -2,    2,    1,    2,    0,   -2,    1,    1,   -4,   -1,    8,   -1,    5,    1,    1,   -1,    3,    1,    2,   -2,   -1,    1 ],
  [    2,   -1,   -1,   -1,    1,    0,    0,   -1,    0,   -1,   -1,    2,   -1,   -1,    1,    0,   -1,   -1,    1,    0,    1,    1 ],
  [   -1,    1,    1,    2,    0,   -2,    1,    1,   -3,   -1,    5,   -1,    4,    1,    2,   -1,    2,    1,    1,   -2,   -1,    1 ],
  [    3,    2,   -1,    0,    0,    0,    1,    0,   -2,    1,    1,   -1,    1,    2,   -1,   -1,    1,    0,    0,    0,    0,    1 ],
  [    5,   -4,    1,    1,    1,   -3,    1,   -1,   -1,   -2,    1,    1,    2,   -1,    6,    0,    0,    0,    0,   -1,    1,    2 ],
  [   -1,   -1,    1,    0,    0,    0,    0,    0,    0,    0,   -1,    0,   -1,   -1,    0,    2,   -1,    1,   -1,    1,    0,    0 ],
  [    1,    3,    0,    1,    0,   -1,    1,    0,   -3,    0,    3,   -1,    2,    1,    0,   -1,    2,    0,    1,   -1,    0,    1 ],
  [   -2,    2,    1,    1,    0,   -1,    1,    1,   -4,    0,    1,   -1,    1,    0,    0,    1,    0,    2,    0,    0,   -1,    1 ],
  [   -4,    0,    0,    0,    0,    0,   -1,    1,   -1,   -1,    2,    1,    1,    0,    0,   -1,    1,    0,    2,   -1,   -1,    0 ],
  [    4,   -1,    0,   -1,    0,    0,    0,   -1,    2,    1,   -2,    0,   -2,    0,   -1,    1,   -1,    0,   -1,    2,    1,   -1 ],
  [    8,   -5,    0,   -1,    1,    0,    0,   -2,    3,    0,   -1,    1,   -1,    0,    1,    0,    0,   -1,   -1,    1,    2,    0 ],
  [    4,   -4,    1,    1,    0,   -2,    1,    0,   -1,   -1,    1,    1,    1,    1,    2,    0,    1,    1,    0,   -1,    0,    2 ] ]
