apply (tends_uniq ?? xn ?? Hx Hy);
qed.
-(* 3.21 *)
+definition shift : ∀R.∀ml:mlattice R.∀xn:sequence ml.nat → sequence ml ≝
+ λR.λml:mlattice R.λxn:sequence ml.λm:nat.λn.xn (n+m).
+
+definition ank ≝
+ λR.λml:mlattice R.λxn:sequence ml.λk:nat.
+ let rec ank_aux (i : nat) ≝
+ match i with
+ [ O ⇒ (shift ?? xn k) O
+ | S n1 ⇒ (shift ?? xn k) (S n1) ∧ ank_aux n1]
+ in ank_aux.
+
+definition bnk ≝
+ λR.λml:mlattice R.λxn:sequence ml.λk:nat.
+ let rec bnk_aux (i : nat) ≝
+ match i with
+ [ O ⇒ (shift ?? xn k) O
+ | S n1 ⇒ (shift ?? xn k) (S n1) ∨ bnk_aux n1]
+ in bnk_aux.
+
+lemma ank_decreasing:
+ ∀R.∀ml:mlattice R.∀xn:sequence ml.∀m.decreasing ? (ank ?? xn m).
+intros (R ml xn m); unfold; intro n; simplify; apply lem;
+qed.
+
+(* 3.26 *)
+lemma ankS:
+ ∀R.∀ml:mlattice R.∀xn:sequence ml.∀k,n:nat.
+ ((ank ?? xn k) (S n)) ≈ (xn k ∧ ank ?? xn (S k) n).
+intros (R ml xn k n); elim n; simplify; [apply meet_comm]
+simplify in H; apply (Eq≈ ? (feq_ml ???? (H))); clear H;
+apply (Eq≈ ? (meet_assoc ????));
+apply (Eq≈ ?? (eq_sym ??? (meet_assoc ????)));
+apply feq_mr; rewrite > sym_plus in ⊢ (? ? ? (? ? ? (? (? %))));
+simplify; rewrite > sym_plus in ⊢ (? ? ? (? ? ? (? (? %))));
+apply meet_comm;
+qed.
+
+
+
\ No newline at end of file
intro H1; apply H; clear H; apply (strong_extm ???? H1);
qed.
+lemma feq_mr: ∀ml:lattice.∀a,b,c:ml. a ≈ b → (a ∧ c) ≈ (b ∧ c).
+intros (l a b c H);
+apply (Eq≈ ? (meet_comm ???)); apply (Eq≈ ?? (meet_comm ???));
+apply feq_ml; assumption;
+qed.
+
lemma feq_jl: ∀ml:lattice.∀a,b,c:ml. a ≈ b → (c ∨ a) ≈ (c ∨ b).
intros (l a b c H); unfold eq in H ⊢ %; unfold Not in H ⊢ %;
intro H1; apply H; clear H; apply (strong_extj ???? H1);
apply eq_sym; apply absorbjm;
qed.
-
+lemma lem: ∀ml:lattice.∀a,b:ml.(a ∧ b) ≤ b.
+intros; unfold le; unfold excess_of_lattice; unfold excl; simplify;
+intro H; apply (ap_coreflexive ? (a∧b));
+apply (Ap≫ (a∧(b∧b)) (feq_ml ???? (meet_refl ? b)));
+apply (Ap≫ ? (meet_assoc ????)); assumption;
+qed.
+