More ZUtil

After    | File Name                                       | Before   || Change
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1m42.25s | Total                                           | 1m43.34s || -0m01.09s
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0m47.63s | Specific/GF25519                                | 0m47.32s || +0m00.31s
0m11.34s | Experiments/SpecEd25519                         | 0m11.30s || +0m00.03s
0m08.26s | Specific/GF1305                                 | 0m08.34s || -0m00.08s
0m03.78s | ModularArithmetic/Pow2BaseProofs                | 0m03.81s || -0m00.03s
0m03.65s | ModularArithmetic/Tutorial                      | 0m03.80s || -0m00.14s
0m03.58s | BaseSystemProofs                                | 0m03.73s || -0m00.14s
0m02.77s | ModularArithmetic/ModularBaseSystemOpt          | 0m02.89s || -0m00.12s
0m02.28s | Util/ZUtil                                      | 0m02.27s || +0m00.00s
0m01.52s | Encoding/PointEncodingPre                       | 0m01.55s || -0m00.03s
0m01.47s | ModularArithmetic/PrimeFieldTheorems            | 0m01.55s || -0m00.08s
0m01.45s | ModularArithmetic/ModularArithmeticTheorems     | 0m01.54s || -0m00.09s
0m01.15s | ModularArithmetic/ExtendedBaseVector            | 0m01.21s || -0m00.06s
0m01.13s | BaseSystem                                      | 0m01.17s || -0m00.04s
0m00.97s | ModularArithmetic/ModularBaseSystemProofs       | 0m00.98s || -0m00.01s
0m00.96s | Experiments/SpecificCurve25519                  | 0m01.00s || -0m00.04s
0m00.93s | Experiments/DerivationsOptionRectLetInEncoding  | 0m00.99s || -0m00.05s
0m00.92s | ModularArithmetic/BarrettReduction/Z            | 0m00.95s || -0m00.02s
0m00.84s | ModularArithmetic/ModularBaseSystemField        | 0m00.89s || -0m00.05s
0m00.83s | Util/NumTheoryUtil                              | 0m00.84s || -0m00.01s
0m00.73s | ModularArithmetic/ModularBaseSystemListProofs   | 0m00.74s || -0m00.01s
0m00.65s | Encoding/ModularWordEncodingTheorems            | 0m00.70s || -0m00.04s
0m00.62s | Testbit                                         | 0m00.63s || -0m00.01s
0m00.56s | ModularArithmetic/ExtPow2BaseMulProofs          | 0m00.61s || -0m00.04s
0m00.56s | Encoding/ModularWordEncodingPre                 | 0m00.58s || -0m00.01s
0m00.55s | Spec/ModularWordEncoding                        | 0m00.59s || -0m00.03s
0m00.53s | ModularArithmetic/ModularBaseSystemList         | 0m00.59s || -0m00.05s
0m00.52s | ModularArithmetic/ModularBaseSystem             | 0m00.54s || -0m00.02s
0m00.50s | ModularArithmetic/PseudoMersenneBaseParamProofs | 0m00.59s || -0m00.08s
0m00.46s | ModularArithmetic/Pre                           | 0m00.46s || +0m00.00s
0m00.39s | ModularArithmetic/PseudoMersenneBaseParams      | 0m00.40s || -0m00.01s
0m00.38s | ModularArithmetic/Pow2Base                      | 0m00.43s || -0m00.04s
0m00.34s | Spec/ModularArithmetic                          | 0m00.36s || -0m00.01s

1 files changed, 10 insertions, 2 deletions

diff --git a/src/Util/ZUtil.v b/src/Util/ZUtil.v
index e20ff9010..708eb5417 100644
--- a/src/Util/ZUtil.v
+++ b/src/Util/ZUtil.v
@@ -22,7 +22,7 @@ Hint Resolve (fun a b H => proj1 (Z.mod_pos_bound a b H)) (fun a b H => proj2 (Z
     which can reasonably be said to "simplify" the goal, should go in
     this database. *)
 Create HintDb zsimplify discriminated.
-Hint Rewrite Z.div_1_r Z.mul_1_r Z.mul_1_l Z.sub_diag Z.mul_0_r Z.mul_0_l Z.add_0_l Z.add_0_r Z.opp_involutive Z.sub_0_r Z_mod_same_full : zsimplify.
+Hint Rewrite Z.div_1_r Z.mul_1_r Z.mul_1_l Z.sub_diag Z.mul_0_r Z.mul_0_l Z.add_0_l Z.add_0_r Z.opp_involutive Z.sub_0_r Z_mod_same_full Z.sub_simpl_r Z.sub_simpl_l : zsimplify.
 Hint Rewrite Z.div_mul Z.div_1_l Z.div_same Z.mod_same Z.div_small Z.mod_small Z.div_add Z.div_add_l Z.mod_add Z.div_0_l using lia : zsimplify.
 
 (** "push" means transform [-f x] to [f (-x)]; "pull" means go the other way *)
@@ -44,7 +44,7 @@ Hint Rewrite <- Z.opp_add_distr : pull_Zopp.
 Hint Rewrite <- Z.div_opp_l_nz Z.div_opp_l_z using lia : push_Zopp.
 Hint Rewrite <- Z.mul_opp_l : push_Zopp.
 Hint Rewrite Z.opp_add_distr : push_Zopp.
-Hint Rewrite Z.pow_sub_r Z.pow_div_l using lia : push_Zpow.
+Hint Rewrite Z.pow_sub_r Z.pow_div_l Z.pow_twice_r using lia : push_Zpow.
 Hint Rewrite <- Z.pow_sub_r Z.pow_div_l using lia : pull_Zpow.
 Hint Rewrite Z.mul_add_distr_l Z.mul_add_distr_r Z.mul_sub_distr_l Z.mul_sub_distr_r : push_Zmul.
 Hint Rewrite <- Z.mul_add_distr_l Z.mul_add_distr_r Z.mul_sub_distr_l Z.mul_sub_distr_r : pull_Zmul.
@@ -1056,6 +1056,14 @@ Module Z.
   Definition mul_div_le'
     := fun x y z w p H0 H1 H2 H3 => @Z.le_trans _ _ w (@Z.mul_div_le x y z H0 H1 H2 H3) p.
   Hint Resolve mul_div_le' : zarith.
+
+  Lemma two_p_two_eq_four : 2^(2) = 4.
+  Proof. reflexivity. Qed.
+  Hint Rewrite <- two_p_two_eq_four : push_Zpow.
+
+  Lemma two_sub_sub_inner_sub x y z : 2 * x - y - (x - z) = x - y + z.
+  Proof. clear; lia. Qed.
+  Hint Rewrite two_sub_sub_inner_sub : zsimplify.
 End Z.
 
 Module Export BoundsTactics.