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authorCyril Cohen2020-08-11 02:49:27 +0200
committerGitHub2020-08-11 02:49:27 +0200
commit16a8f48a4ac0a871ece84049f6271a6926e850e3 (patch)
tree10aca5d616887d9e363b39722f44ef72d8743f9f /mathcomp
parent0265476610747475a856f0560a86fe3b5409469f (diff)
parenta79e8b941cfd4a3343a90f14fba3b7f70293e679 (diff)
Merge pull request #541 from chdoc/properC
lemmas for proper and setC
Diffstat (limited to 'mathcomp')
-rw-r--r--mathcomp/ssreflect/finset.v9
1 files changed, 9 insertions, 0 deletions
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}.