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authorChristian Doczkal2020-06-26 11:25:15 +0200
committerChristian Doczkal2020-06-26 11:25:15 +0200
commita79e8b941cfd4a3343a90f14fba3b7f70293e679 (patch)
treee99e0f620b040c187f5413f7a815ea4aceae1a80
parent3728862662bd0a5b836dfa746921954604d051ec (diff)
lemmas for proper and setC
-rw-r--r--CHANGELOG_UNRELEASED.md2
-rw-r--r--mathcomp/ssreflect/finset.v9
2 files changed, 10 insertions, 1 deletions
diff --git a/CHANGELOG_UNRELEASED.md b/CHANGELOG_UNRELEASED.md
index 7a03f8e..935d165 100644
--- a/CHANGELOG_UNRELEASED.md
+++ b/CHANGELOG_UNRELEASED.md
@@ -19,7 +19,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
`card_le1_eqP` (generalizes `fintype_le1P`),
- in `finset.v`, neq lemmas: `set_enum`, `cards_eqP`, `cards2P`
- in `fingraph.v`, new lemmas: `fcard_gt0P`, `fcard_gt1P`
-
+- in `finset.v`, new lemmas: `properC`, `properCr`, `properCl`
### Changed
diff --git a/mathcomp/ssreflect/finset.v b/mathcomp/ssreflect/finset.v
index f4c1dd5..9bd8c1f 100644
--- a/mathcomp/ssreflect/finset.v
+++ b/mathcomp/ssreflect/finset.v
@@ -639,6 +639,9 @@ Proof. by apply/setP=> x; rewrite !inE. Qed.
Lemma setCT : ~: [set: T] = set0.
Proof. by rewrite -setC0 setCK. Qed.
+Lemma properC A B : (~: B \proper ~: A) = (A \proper B).
+Proof. by rewrite !properE !setCS. Qed.
+
(* difference *)
Lemma setDP A B x : reflect (x \in A /\ x \notin B) (x \in A :\: B).
@@ -982,6 +985,12 @@ Qed.
Lemma properD A B C : (A \proper B :\: C) -> (A \proper B) && [disjoint A & C].
Proof. by rewrite setDE disjoints_subset => /properI/andP[-> /proper_sub]. Qed.
+Lemma properCr A B : (A \proper ~: B) = (B \proper ~: A).
+Proof. by rewrite -properC setCK. Qed.
+
+Lemma properCl A B : (~: A \proper B) = (~: B \proper A).
+Proof. by rewrite -properC setCK. Qed.
+
End setOps.
Arguments set1P {T x a}.