O = (0, 0)
a = Line(O, (0, 1))
b = Line(O, (1, 0))
p = 0.7 (slider from 0.2 to 1, step 0.1)
c = Line((0, (4 * p)), (1, (4 * p)))
d = Line((0, ((-4) * p)), (1, ((-4) * p)))
e = Line(((3 * p), 0), ((3 * p), 1))
f = Line((((-3) * p), 0), (((-3) * p), 1))
P_1 = Intersect(a, c)
P_2 = Intersect(a, d)
P_3 = Intersect(b, f)
P_4 = Intersect(b, e)
g = Line((((-4) * p), 0), (((-4) * p), 1))
h = Line(((4 * p), 0), ((4 * p), 1))
F_1 = Intersect(b, h)
F_2 = Intersect(b, g)
k = Ellipse(F_1, F_2, (5 * p))
M = Point(k)
i = Segment(M, F_1)
j = Segment(M, F_2)
enveloppe = 3 (slider from (2 * p) to (10 * p), step 0.1)
t = Circle(P_4, enveloppe)
m = Line(P_1, P_4)
n = Line(P_2, P_4)
A, B = Intersect(t, m)
C, D = Intersect(t, n)
q = CircleArc(P_4, B, D)
r = Circle(P_2, D)
s = Line(P_2, P_3)
E, F = Intersect(r, s)
c_1 = CircleArc(P_2, D, F)
d_1 = Circle(P_3, F)
a_1 = Line(P_1, P_3)
G, H = Intersect(d_1, a_1)
e_1 = CircleArc(P_3, F, H)
f_1 = Circle(P_1, H)
g_1 = CircleArc(P_1, H, B)
b_1 = Segment(P_1, B)
h_1 = Segment(P_1, H)
i_1 = Segment(P_2, D)
j_1 = Segment(P_2, F)