A = (6, -1)
B = (6, 1)
a = Line(A, B)
C = (9, -1)
D = (9, 1)
b = Line(C, D)
E = (5, 0)
E' = Mirror(E, a)
E'' = Mirror(E', b)
c = Segment(E, E')
d = Segment(E', E'')