O = (0, 0, 0)
G = (0, 0, 1)
F = (0, 2, 1)
A = (4, 0, 0)
B = (4, 2, 0)
D = (4, 0, 1)
a = Segment(A, B)
d = Segment(D, A)
h = Segment(F, G)
i = Segment(G, D)
k = Segment(O, G)
l = Segment(O, A)
E = (4, 2, 1)
b = Segment(B, E)
c = Segment(E, D)
e = Segment(E, F)
C = (0, 2, 0)
f = Segment(F, C)
g = Segment(C, B)
j = Segment(O, C)