##[ ncases n; /2/;
##| /3/;
##| #m; #Hind; ncases Hind;/3/;
- (*
- ##[/2/; ##|#H; nwhd;
- napply or_introl;
- napply eq_f2; /3/; *)
##]
nqed.
#n; nelim n; nnormalize; //; nqed.
ntheorem assoc_plus1: ∀a,b,c. c + (b + a) = b + c + a.
-//; nqed.
+//; nqed.
ntheorem injective_plus_r: ∀n:nat.injective nat nat (λm.n+m).
#n; nelim n; nnormalize; /3/; nqed.
ntheorem le_O_n : ∀n:nat. O ≤ n.
#n; nelim n; /2/; nqed.
+ntheorem nboh: 0 ≤ 0 + 0.
+//; nqed.
+
ntheorem le_n_Sn : ∀n:nat. n ≤ S n.
/2/; nqed.
#n; #m; #lenm; nelim lenm; /2/;nqed.
ntheorem le_S_S_to_le: ∀n,m:nat. S n ≤ S m → n ≤ m.
-(* XXX *) nletin hint ≝ monotonic.
-#a; #b; #H; napplyS monotonic_pred;
/2/; nqed.
(* this are instances of the le versions
(* le and eq *)
ntheorem le_to_le_to_eq: ∀n,m. n ≤ m → m ≤ n → n = m.
-napply nat_elim2;
-#n; #H1; #H2; /4/;
- nqed.
+napply nat_elim2; /4/;
+nqed.
ntheorem lt_O_S : ∀n:nat. O < S n.
/2/; nqed.