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(* 02110-1301 USA                                                     *)
(** prime. The primality predicate.  @author Olga Caprotti and Martijn Oostdijk @version $Revision$ *)
(** * Primality on nat *)
Definition Prime (n : nat) : Prop :=
n > 1 /\ (forall q : nat, Divides q n -> q = 1 \/ q = n).
(** Prime with bounded all quantifier. *)
Definition bPrime (n : nat) :=
n > 1 /\ (forall q : nat, q < S n -> Divides q n -> q = 1 \/ q = n).
(** Prime is decidable. *)
(** Non-primes n>1 have non-trivial divisors. *)
(** Non-primes n>1 have prime-divisors. *)
(** Prime(n) if all prime divisors > sqrt(n). *)
(** Two is a prime. *)
(** * Primality on Z *)
(** ZPrime, just like Prime but uses only Z. *)
Definition ZPrime (n : Z) : Prop :=
(n > 1)%Z /\ (forall q : Z, (q >= 0)%Z -> ZDivides q n -> q = 1%Z \/ q = n).

Lemma zprimeprime : forall n : Z, ZPrime n -> Prime (Z.abs_nat n).