-r

r

b = 2.5 (slider from -6 to 6, step 0.1)
phi(x) = exp(-x^(2.0) / 2.0) / sqrt(2.0 * 3.141592653589793)
r = 1 (slider from 0 to 5, step 0.1)
P = Integral(phi, -(r), r)
a: b - 2.0 * r
p = Integral(phi, a, b)
H: (-(r), phi(r))
K: (r, phi(r))
L: (a, phi(r))
M: (b, phi(r))
c = Line(K, H)
A: (a, 0.0)
B: (b, 0.0)
I: (-(r), 0.0)
J: (r, 0.0)
poly1, a_1, l, m, b_1 = Polygon(A, L, M, B)