a(x, y) = If[x^(2) + y^(2) < 1, (x^(2) + y^(2))^(1 / 2)]
A = Intersect(yAxis, xAxis)
B = Point(zAxis)
b, c, d, e = Cylinder(A, B, 1)
f = CurveCartesian((0.25 * cos(t)), (0.25 * sin(t)), 0.25, t, 0, (2 * π))
g = CurveCartesian((0.5 * cos(t)), (0.5 * sin(t)), 0.5, t, 0, (2 * π))
h = CurveCartesian((0.75 * cos(t)), (0.75 * sin(t)), 0.75, t, 0, (2 * π))
l1 = Sequence((cos((t * 30°)), sin((t * 30°)), 1), t, 0, 11)
l2 = Sequence(Segment[A, Element[l1, n]], n, 1, 12)
E = (-0.639863670514308, 5.83826869749334)