(* *)
(**************************************************************************)
-set "baseuri" "cic:/matita/nat/ord".
-
include "datatypes/constructors.ma".
include "nat/exp.ma".
-include "nat/gcd.ma".
-include "nat/relevant_equations.ma". (* required by auto paramod *)
+include "nat/nth_prime.ma".
+include "nat/gcd.ma". (* for some properties of divides *)
+include "nat/relevant_equations.ma". (* required by autobatch paramod *)
let rec p_ord_aux p n m \def
match n \mod m with
apply le_times_l.
assumption.
apply le_times_r.assumption.
-alias id "not_eq_to_le_to_lt" = "cic:/matita/algebra/finite_groups/not_eq_to_le_to_lt.con".
-apply not_eq_to_le_to_lt.
+ apply not_eq_to_le_to_lt.
unfold.intro.apply H1.
rewrite < H3.
apply (witness ? r r ?).simplify.apply plus_n_O.
unfold.apply le_n.assumption.symmetry.assumption.
qed.
+theorem eq_p_ord_q_O: ∀p,n,q. p_ord n p = pair ? ? q O → n=O ∧ q=O.
+ intros 2;
+ cases n;
+ [ cases p; simplify; intros; destruct H; split; reflexivity;
+ | cases p;
+ [ intros;
+ simplify in H;
+ destruct H
+ | cases n2;
+ [ intros;
+ simplify in H;
+ rewrite < minus_n_O in H;
+ simplify in H;
+ change in H:(? ? match % return ? with [_⇒?|_⇒?] ?) with (mod n1 (S O));
+ rewrite > mod_SO in H;
+ simplify in H;
+ change in H:(? ? match ? ? (? %) ? return ? with [_⇒?] ?) with (div n1 (S O));
+ rewrite > div_SO in H;
+ simplify in H;
+
+ letin H1 ≝ (p_ord_aux_to_exp n1 (S n1) 1); clearbody H1;
+ elim (p_ord_aux n1 (S n1) 1) in H H1 (q' r'); simplify in H H1;
+ destruct H;
+ lapply (H1 q' O (le_n ?) (refl_eq ? ?));
+ rewrite < times_n_O in Hletin;
+ destruct Hletin
+ | intros;
+ lapply (p_ord_to_exp1 ? ? ? ? ? ? H);
+ [ apply le_S_S;
+ apply le_S_S;
+ apply le_O_n
+ | apply le_S_S;
+ apply le_O_n
+ | cases Hletin;
+ elim H1;
+ apply (witness ? O O);
+ rewrite < times_n_O;
+ reflexivity]]]]
+qed.
+
theorem p_ord_times: \forall p,a,b,qa,ra,qb,rb. prime p
\to O \lt a \to O \lt b
\to p_ord a p = pair nat nat qa ra
elim (divides_times_to_divides ? ? ? H H9).
apply (absurd ? ? H10 H5).
apply (absurd ? ? H10 H7).
-(* rewrite > H6.
-rewrite > H8. *)
-auto paramodulation.
+(* REGRESSION *)
+rewrite > H6.
+rewrite > H8.
+autobatch paramodulation.
unfold prime in H. elim H. assumption.
qed.
apply exp_n_SO.
qed.
+(* p_ord and divides *)
theorem divides_to_p_ord: \forall p,a,b,c,d,n,m:nat.
O < n \to O < m \to prime p
\to divides n m \to p_ord n p = pair ? ? a b \to
apply (lt_to_not_eq O ? H).
rewrite > H7.
rewrite < H10.
- auto
+ autobatch;assumption;
]
|elim c
[rewrite > sym_gcd.
|apply lt_O_exp.apply lt_to_le.assumption
|rewrite > sym_gcd.
(* hint non trova prime_to_gcd_SO e
- auto non chiude il goal *)
+ autobatch non chiude il goal *)
apply prime_to_gcd_SO
[assumption|assumption]
|assumption
|apply lt_O_exp.apply lt_to_le.assumption
|rewrite > sym_gcd.
(* hint non trova prime_to_gcd_SO e
- auto non chiude il goal *)
+ autobatch non chiude il goal *)
apply prime_to_gcd_SO
[assumption|assumption]
|rewrite > sym_gcd. assumption
]
|elim H2.assumption
]
-qed.
+qed.
+
+(* p_ord and primes *)
+theorem not_divides_to_p_ord_O: \forall n,i.
+Not (divides (nth_prime i) n) \to p_ord n (nth_prime i) =
+pair nat nat O n.
+intros.
+apply p_ord_exp1
+ [apply lt_O_nth_prime_n
+ |assumption
+ |autobatch
+ ]
+qed.
+
+theorem p_ord_O_to_not_divides: \forall n,i,r.
+O < n \to
+p_ord n (nth_prime i) = pair nat nat O r
+\to Not (divides (nth_prime i) n).
+intros.
+lapply (p_ord_to_exp1 ? ? ? ? ? ? H1)
+ [apply lt_SO_nth_prime_n
+ |assumption
+ |elim Hletin.
+ simplify in H3.
+ rewrite > H3.
+ rewrite < plus_n_O.
+ assumption
+ ]
+qed.
+
+theorem p_ord_to_not_eq_O : \forall n,p,q,r.
+ (S O) < n \to
+ p_ord n (nth_prime p) = pair nat nat q r \to
+ Not (r=O).
+intros.
+unfold.intro.
+cut (O < n)
+ [lapply (p_ord_to_exp1 ? ? ? ? ? ? H1)
+ [apply lt_SO_nth_prime_n.
+ |assumption
+ |elim Hletin.
+ apply (lt_to_not_eq ? ? Hcut).
+ rewrite > H4.
+ rewrite > H2.
+ apply times_n_O
+ ]
+ |apply (trans_lt ? (S O))[apply lt_O_S|assumption]
+ ]
+qed.
definition ord :nat \to nat \to nat \def
\lambda n,p. fst ? ? (p_ord n p).
]
qed.
-(* p_ord_inv is the inverse of ord *)
+(* properties of ord e ord_rem *)
+
+theorem ord_times: \forall p,m,n.O<m \to O<n \to prime p \to
+ord (m*n) p = ord m p+ord n p.
+intros.unfold ord.
+rewrite > (p_ord_times ? ? ? (ord m p) (ord_rem m p) (ord n p) (ord_rem n p))
+ [reflexivity
+ |assumption
+ |assumption
+ |assumption
+ |unfold ord.unfold ord_rem.apply eq_pair_fst_snd
+ |unfold ord.unfold ord_rem.apply eq_pair_fst_snd
+ ]
+qed.
+
+theorem ord_exp: \forall p,m.S O < p \to
+ord (exp p m) p = m.
+intros.
+unfold ord.
+rewrite > (p_ord_exp1 p (exp p m) m (S O))
+ [reflexivity
+ |apply lt_to_le.assumption
+ |intro.apply (lt_to_not_le ? ? H).
+ apply divides_to_le
+ [apply lt_O_S
+ |assumption
+ ]
+ |apply times_n_SO
+ ]
+qed.
+
+theorem not_divides_to_ord_O:
+\forall p,m. prime p \to \lnot (divides p m) \to
+ord m p = O.
+intros.unfold ord.
+rewrite > (p_ord_exp1 p m O m)
+ [reflexivity
+ |apply prime_to_lt_O.assumption
+ |assumption
+ |simplify.apply plus_n_O
+ ]
+qed.
+
+theorem ord_O_to_not_divides:
+\forall p,m. O < m \to prime p \to ord m p = O \to
+\lnot (divides p m).
+intros.
+lapply (p_ord_to_exp1 p m (ord m p) (ord_rem m p))
+ [elim Hletin.
+ rewrite > H4.
+ rewrite > H2.
+ rewrite > sym_times.
+ rewrite < times_n_SO.
+ assumption
+ |apply prime_to_lt_SO.assumption
+ |assumption
+ |unfold ord.unfold ord_rem.apply eq_pair_fst_snd
+ ]
+qed.
+
+theorem divides_to_not_ord_O:
+\forall p,m. O < m \to prime p \to divides p m \to
+\lnot(ord m p = O).
+intros.intro.
+apply (ord_O_to_not_divides ? ? H H1 H3).
+assumption.
+qed.
+
+theorem not_ord_O_to_divides:
+\forall p,m. O < m \to prime p \to \lnot (ord m p = O) \to
+divides p m.
+intros.
+rewrite > (exp_ord p) in ⊢ (? ? %)
+ [apply (trans_divides ? (exp p (ord m p)))
+ [generalize in match H2.
+ cases (ord m p);intro
+ [apply False_ind.apply H3.reflexivity
+ |simplify.autobatch
+ ]
+ |autobatch
+ ]
+ |apply prime_to_lt_SO.
+ assumption
+ |assumption
+ ]
+qed.
+
+theorem not_divides_ord_rem: \forall m,p.O< m \to S O < p \to
+\lnot (divides p (ord_rem m p)).
+intros.
+elim (p_ord_to_exp1 p m (ord m p) (ord_rem m p))
+ [assumption
+ |assumption
+ |assumption
+ |unfold ord.unfold ord_rem.apply eq_pair_fst_snd
+ ]
+qed.
+
+theorem ord_ord_rem: \forall p,q,m. O < m \to
+prime p \to prime q \to
+q < p \to ord (ord_rem m p) q = ord m q.
+intros.
+rewrite > (exp_ord p) in ⊢ (? ? ? (? % ?))
+ [rewrite > ord_times
+ [rewrite > not_divides_to_ord_O in ⊢ (? ? ? (? % ?))
+ [reflexivity
+ |assumption
+ |intro.
+ apply (lt_to_not_eq ? ? H3).
+ apply (divides_exp_to_eq ? ? ? H2 H1 H4)
+ ]
+ |apply lt_O_exp.
+ apply (ltn_to_ltO ? ? H3)
+ |apply lt_O_ord_rem
+ [elim H1.assumption
+ |assumption
+
+ ]
+ |assumption
+ ]
+ |elim H1.assumption
+ |assumption
+ ]
+qed.
+
+theorem lt_ord_rem: \forall n,m. prime n \to O < m \to
+divides n m \to ord_rem m n < m.
+intros.
+elim (le_to_or_lt_eq (ord_rem m n) m)
+ [assumption
+ |apply False_ind.
+ apply (ord_O_to_not_divides ? ? H1 H ? H2).
+ apply (inj_exp_r n)
+ [apply prime_to_lt_SO.assumption
+ |apply (inj_times_l1 m)
+ [assumption
+ |rewrite > sym_times in ⊢ (? ? ? %).
+ rewrite < times_n_SO.
+ rewrite < H3 in ⊢ (? ? (? ? %) ?).
+ apply sym_eq.
+ apply exp_ord
+ [apply prime_to_lt_SO.assumption
+ |assumption
+ ]
+ ]
+ ]
+ |apply divides_to_le
+ [assumption
+ |apply divides_ord_rem
+ [apply prime_to_lt_SO.assumption
+ |assumption
+ ]
+ ]
+ ]
+qed.
+
+(* p_ord_inv is used to encode the pair ord and rem into
+ a single natural number. *)
+
definition p_ord_inv \def
\lambda p,m,x.
match p_ord x p with
intros.rewrite > eq_p_ord_inv.
apply mod_plus_times.
assumption.
-qed.
\ No newline at end of file
+qed.