R21 = (0, -2)
R22 = (15, 1)
f = Line(R21, R22)
R11 = (0, -3)
R12 = (15, -3)
g = Line(R11, R12)
A1 = Point(g)
B2 = Point(f)
h = Segment(A1, B2)
C1 = Point(g)
j = Segment(B2, C1)
A2 = Point(f)
B1 = Intersect(g, Line[A2, j])
m = Segment(A2, B1)
C2 = Intersect(f, Line[B1, h])
k = Segment(B1, C2)
D2 = Intersect(f, Line[C1, h])
i = Segment(C1, D2)
D1 = Intersect(g, Line[C2, j])
l = Segment(C2, D1)