liste1 = Sequence(Sequence[Sequence[(j1, j2, j3), j1, -2, 2], j2, -2, 2], j3, -2, 2)
liste2 = Sequence(Sequence[Sequence[Segment[(j1, j2, j3), (j1, j2, j3 + 1)], j1, -2, 2], j2, -2, 2], j3, -2, 1)
liste4 = Sequence(Sequence[Sequence[Segment[(j1, j2, j3), (j1, j2 + 1, j3)], j1, -2, 2], j2, -2, 1], j3, -2, 2)
liste3 = Sequence(Sequence[Sequence[Segment[(j1, j2, j3), (j1 + 1, j2, j3)], j1, -2, 1], j2, -2, 2], j3, -2, 2)
a = Plane((1, 1, 3), (2, 1, 1), (3, 2, 2))
b = Sphere((0.8, 0.4, 1.2), 1)