Neuberechnung mit F9 bzw Strg+R

λ = 2 (slider from 1 to 5, step 1)
N = 20 (slider from 1 to 200, step 1)
L1 = Sequence((-1 / λ * ln(RandomUniform[0, 1])), n, 1, N)
L2 = Sequence(Sum[L1, n], n, 1, N)
L3 = Sequence((Sum[L1, n], 0), n, 1, N)
L4 = Sequence(PolyLine[(Element[L2, n], n), (Element[L2, n + 1], n), (Element[L2, n + 1], n + 1)], n, 1, N - 1)
d = Segment(Element[L3, 1], (Element[L1, 1], 1))