proposition: Lemma pi_of_prime p : prime p -> \pi(p) =i (p : nat_pred).
proof: Proof. by move=> pr_p q; rewrite /pi_of primes_prime // mem_seq1. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(fintype div bigop)