Číslo kroku

S = (4.872, 1.7356)
D = (9.5426, -2.3058)
k = Circle(S, D)
A = (1.6292, 4.0588)
B = (4.1702, 0.0174)
f = LineBisector(A, B)
g = Line(A, S)
E, F = Intersect(k, g)
E_1 = Midpoint(E, A)
F_1 = Midpoint(A, F)
p = Ellipse(A, S, F_1)
S_1, S_2 = Intersect(p, f)
k_1 = Circle(S_1, A)
k_2 = Circle(S_2, A)
a = 0 (slider from 0 to 8, step 1)