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-rw-r--r--src/Util/ZUtil.v60
1 files changed, 50 insertions, 10 deletions
diff --git a/src/Util/ZUtil.v b/src/Util/ZUtil.v
index aa55f373c..f484a86c7 100644
--- a/src/Util/ZUtil.v
+++ b/src/Util/ZUtil.v
@@ -1223,6 +1223,16 @@ Module Z.
Qed.
Hint Rewrite <- add_mod_r using lia : pull_Zmod.
+ (** Give alternate names for the next three lemmas, for consistency *)
+ Lemma sub_mod a b n : n <> 0 -> (a - b) mod n = ((a mod n) - (b mod n)) mod n.
+ Proof. auto using Zminus_mod. Qed.
+
+ Lemma sub_mod_l a b n : n <> 0 -> (a - b) mod n = ((a mod n) - b) mod n.
+ Proof. auto using Zminus_mod_idemp_l. Qed.
+
+ Lemma sub_mod_r a b n : n <> 0 -> (a - b) mod n = (a - (b mod n)) mod n.
+ Proof. auto using Zminus_mod_idemp_r. Qed.
+
Definition NoZMod (x : Z) := True.
Ltac NoZMod :=
lazymatch goal with
@@ -1386,22 +1396,34 @@ Ltac push_Zmod :=
repeat match goal with
| _ => progress autorewrite with push_Zmod
| [ |- context[(?x * ?y) mod ?z] ]
- => rewrite (Z.mul_mod_push x y z) by (Z.NoZMod || lia)
- | [ |- context[(?x * ?y) mod ?z] ]
- => rewrite (Z.mul_mod_l_push x y z) by (Z.NoZMod || lia)
- | [ |- context[(?x * ?y) mod ?z] ]
- => rewrite (Z.mul_mod_r_push x y z) by (Z.NoZMod || lia)
+ => first [ rewrite (Z.mul_mod_push x y z) by (Z.NoZMod || lia)
+ | rewrite (Z.mul_mod_l_push x y z) by (Z.NoZMod || lia)
+ | rewrite (Z.mul_mod_r_push x y z) by (Z.NoZMod || lia) ]
+ | [ |- context[(?x + ?y) mod ?z] ]
+ => first [ rewrite (Z.add_mod_push x y z) by (Z.NoZMod || lia)
+ | rewrite (Z.add_mod_l_push x y z) by (Z.NoZMod || lia)
+ | rewrite (Z.add_mod_r_push x y z) by (Z.NoZMod || lia) ]
+ | [ |- context[(?x - ?y) mod ?z] ]
+ => first [ rewrite (Z.sub_mod_push x y z) by (Z.NoZMod || lia)
+ | rewrite (Z.sub_mod_l_push x y z) by (Z.NoZMod || lia)
+ | rewrite (Z.sub_mod_r_push x y z) by (Z.NoZMod || lia) ]
end.
Ltac push_Zmod_hyps :=
repeat match goal with
| _ => progress autorewrite with push_Zmod in * |-
| [ H : context[(?x * ?y) mod ?z] |- _ ]
- => rewrite (Z.mul_mod_push x y z) in H by (Z.NoZMod || lia)
- | [ H : context[(?x * ?y) mod ?z] |- _ ]
- => rewrite (Z.mul_mod_l_push x y z) in H by (Z.NoZMod || lia)
- | [ H : context[(?x * ?y) mod ?z] |- _ ]
- => rewrite (Z.mul_mod_r_push x y z) in H by (Z.NoZMod || lia)
+ => first [ rewrite (Z.mul_mod_push x y z) in H by (Z.NoZMod || lia)
+ | rewrite (Z.mul_mod_l_push x y z) in H by (Z.NoZMod || lia)
+ | rewrite (Z.mul_mod_r_push x y z) in H by (Z.NoZMod || lia) ]
+ | [ H : context[(?x + ?y) mod ?z] |- _ ]
+ => first [ rewrite (Z.add_mod_push x y z) in H by (Z.NoZMod || lia)
+ | rewrite (Z.add_mod_l_push x y z) in H by (Z.NoZMod || lia)
+ | rewrite (Z.add_mod_r_push x y z) in H by (Z.NoZMod || lia) ]
+ | [ H : context[(?x - ?y) mod ?z] |- _ ]
+ => first [ rewrite (Z.sub_mod_push x y z) in H by (Z.NoZMod || lia)
+ | rewrite (Z.sub_mod_l_push x y z) in H by (Z.NoZMod || lia)
+ | rewrite (Z.sub_mod_r_push x y z) in H by (Z.NoZMod || lia) ]
end.
Ltac has_no_mod x z :=
@@ -1420,5 +1442,23 @@ Ltac pull_Zmod :=
| [ |- context[(?x * (?y mod ?z)) mod ?z] ]
=> has_no_mod x z; has_no_mod y z;
rewrite <- (Z.mul_mod_r x y z) by lia
+ | [ |- context[((?x mod ?z) + (?y mod ?z)) mod ?z] ]
+ => has_no_mod x z; has_no_mod y z;
+ rewrite <- (Z.add_mod x y z) by lia
+ | [ |- context[((?x mod ?z) + ?y) mod ?z] ]
+ => has_no_mod x z; has_no_mod y z;
+ rewrite <- (Z.add_mod_l x y z) by lia
+ | [ |- context[(?x + (?y mod ?z)) mod ?z] ]
+ => has_no_mod x z; has_no_mod y z;
+ rewrite <- (Z.add_mod_r x y z) by lia
+ | [ |- context[((?x mod ?z) - (?y mod ?z)) mod ?z] ]
+ => has_no_mod x z; has_no_mod y z;
+ rewrite <- (Z.sub_mod x y z) by lia
+ | [ |- context[((?x mod ?z) - ?y) mod ?z] ]
+ => has_no_mod x z; has_no_mod y z;
+ rewrite <- (Z.sub_mod_l x y z) by lia
+ | [ |- context[(?x - (?y mod ?z)) mod ?z] ]
+ => has_no_mod x z; has_no_mod y z;
+ rewrite <- (Z.sub_mod_r x y z) by lia
| _ => progress autorewrite with pull_Zmod
end.