proposition: Lemma last_lpeg n (c : configuration 3 n) p (cs := lpeg p c) : last `c[p] cs = c.
proof: Proof. have HHs := @rsym 3; have := last_rpeg c p. rewrite {}/cs /lpeg; case: rpeg => //= c1 cs. by rewrite rev_cons last_rcons. Qed.
imports: mathcomp(all_ssreflect) hanoi(extra gdist ghanoi ghanoi3)