Theorem C: J~U(-1,2):  E[Y] = 4/27  (= 0.148148);  P(J in (-eps,eps)) = 2 eps/3 (linear growth)
  Hoeffding (Y in [-2,2]): P(K<=M) <= exp(-2(m mu - M)^2/(16 m)) <= exp(M mu/4) * exp(-m mu^2/8),  mu^2/8 = 2/729 = 0.002743
  with m_k = ceil(730 log(|k|+2)): exponent 730*mu^2/8 = 2.0027 > 2  -> summable; Sum 1/m_k = inf -> recurrent
  Monte Carlo (evidence): mean Y = 0.14831, P(Y<0) = 0.4444 (frustrated 2-cycles hub-v-hub'-v'-hub occur with prob 2P(Y<0)P(Y>0))

Theorem D: exact P(K_0<=1) with n_0=1, m_0=3 (sum of 3 uniforms): 1/6 (Irwin-Hall F_3(1) = 1/3! = 1/6)
  rigorous lower bound: P(|G|=2) = P(E) >= (5/6) * prod_(j=2..2000)(1-c_j)^2 * (1-6/2000) = 0.1339
  hence 0.1667 <= P(|G(J)|=4) <= 0.8661: |G(J)| is a non-degenerate random variable
  Monte Carlo (evidence, |k|<=7, 4000 reps): P(some K_k<=1) ~ 0.2203
