l1 = Flatten(Join[{Sequence[Sequence[(j, k), j, -5, 5], k, -5, 5], Sequence[Sequence[(j, k), j, -4.5, 4.5], k, -4.5, 4.5]}])
l3 = Flatten(Sequence[Sequence[(j, k), j, -5, 5], k, -5, 5])
l2 = Sequence(Circle[l1(k), sqrt(2) / 4], k, 1, Length[l1])
t = 0 (slider from 0 to 4, step 0.01)
l4 = Sequence(Polygon[(x(l3(k)) - 0.5, y(l3(k)) - 0.5), (x(l3(k)) + 0.5, y(l3(k)) - 0.5), 4], k, 1, Length[l3])