a = 0 (slider from 0 to 7, step 1)
S_1 = (4.97622, -3.4924)
S_2 = (7.23822, -3.0884)
f = Line(S_1, S_2)
C = Point(f)
k_1 = Circle(S_1, C)
k_2 = Circle(S_2, C)
A = Point(k_1)
n = Line(S_1, A)
E = Intersect(k_1, n, 2)
S_3 = Point(n)
k_3 = Circle(S_3, E)
g = OrthogonalLine(C, f)
h, i = Tangent(g, k_3)
F = Intersect(k_3, i, 1)
G = Intersect(k_3, i, 1)
j = Line(G, C)
k = Line(F, C)
H = Intersect(k_3, j, 2)
I = Intersect(k_3, k, 2)
l = LineBisector(H, C)
m = LineBisector(I, C)
S_{6} = Intersect(f, l)
S_{5} = Intersect(f, m)
k_{5} = Circle(S_{5}, C)
k_{6} = Circle(S_{6}, C)
D = Intersect(k_1, n, 1)
p = OrthogonalLine(E, n)
q, r = Tangent(p, k_2)
B = Intersect(k_2, q, 1)
s = Line(E, B)
J = Intersect(k_2, s, 2)
t = LineBisector(E, J)
S_4 = Intersect(n, t)
k_4 = Circle(S_4, E)