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authorGravatar Jason Gross <jagro@google.com>2016-06-30 13:24:23 -0700
committerGravatar Jason Gross <jagro@google.com>2016-06-30 13:24:23 -0700
commit6c6c65eff384182197289797ef58ca78bcfff4dc (patch)
treebe69d58cfb1c90b7bb63047157d7760e4ade63fd /src/Util/NatUtil.v
parente8214b0c7f02c23016a4e95734cae813e115de76 (diff)
Prove that a ^ k <> 0
Diffstat (limited to 'src/Util/NatUtil.v')
-rw-r--r--src/Util/NatUtil.v8
1 files changed, 8 insertions, 0 deletions
diff --git a/src/Util/NatUtil.v b/src/Util/NatUtil.v
index bc2c8425b..0cdfd784f 100644
--- a/src/Util/NatUtil.v
+++ b/src/Util/NatUtil.v
@@ -1,4 +1,5 @@
Require Import Coq.Numbers.Natural.Peano.NPeano Coq.omega.Omega.
+Require Import Coq.micromega.Psatz.
Import Nat.
Local Open Scope nat_scope.
@@ -78,3 +79,10 @@ Proof.
[ rewrite (proj2 (@beq_nat_true_iff _ _) H); reflexivity
| rewrite (proj2 (@beq_nat_false_iff _ _) H); reflexivity ].
Qed.
+
+Lemma pow_nonzero a k : a <> 0 -> a ^ k <> 0.
+Proof.
+ intro; induction k; simpl; nia.
+Qed.
+
+Hint Resolve pow_nonzero : arith.