n=17 R=40.0: 827 reachable points (4293 nodes); types: A0:355, A1:94, A2:46, A3:34, A4:21, A5:15, A6:13, A7:13, A8:13, A9:13, A10:15, A11:21, A12:34, A13:46, A14:94   [0.7s]
Lemma 1: K(gamma_B) == type of Def. 2.1 (mod n-2) for 827 points: failures 0 (non-integer K: 0)   [1.8s]
Descent (Lemma 4b) + invariance of the type under tau_k, mu, rho (Thm 1a): 827 points, 2557 twist steps (max 19 per point; 1102 landed in the neighbouring corner), every step: shorter, reachable, same type; end = diagonal X_0X_(k+1) with k = type: failures 0   [2.6s]
Conj 2.6: 9799 instances (point, l, eps) with both points inside the disc: failures 0; Conj 2.7 (exact length ratio) on the same pairs: failures 0; 14216 instances with the parallel point outside the disc
Conj 2.6/2.7 by exact ray tracing for all points with |B| <= 20.0: 5803 instances, no short trajectory in the predicted direction within 12|B|+5: 0, type failures 0, length-ratio failures 0   [10.3s]
pairs (u,v), |u|,|v| <= 20.0, det(u,v) = sin(2pi/n) exactly: 135   [11.1s]
   (type u, type v) distribution: {(0, 0): 45, (0, 14): 45, (1, 0): 45}; pairs outside the three classes of Step A: 0
Conj 2.3: reachable n-gons found: 45; with vertex types != (A0,A1,...,A(n-3),A0): 0
   Corollary 3.1 (pair of type (A0,A0) <=> spans a reachable n-gon): failures 0; Theorem 3 (v_1,v_2,v_(n-2),v_(n-1) reachable => reachable n-gon): failures 0; vertices outside the disc decided by exact ray tracing: 1672   [26.9s]
exact fallbacks 26123, mp calls 0
