diff options
| author | Cyril Cohen | 2020-10-30 19:42:56 +0100 |
|---|---|---|
| committer | Cyril Cohen | 2020-11-03 15:14:29 +0100 |
| commit | aad2327376b2f76950be51a6bf22b32b0a01b2eb (patch) | |
| tree | 1433612cdaae78d59a634d4d9ccf8e9c96dea4ec /mathcomp/ssreflect | |
| parent | f980c1a579988325efcc5071a8067380a870e403 (diff) | |
Generalizing inj_card_onto and inj_card_bij.
Diffstat (limited to 'mathcomp/ssreflect')
| -rw-r--r-- | mathcomp/ssreflect/fintype.v | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mathcomp/ssreflect/fintype.v b/mathcomp/ssreflect/fintype.v index 422d760..91d5c80 100644 --- a/mathcomp/ssreflect/fintype.v +++ b/mathcomp/ssreflect/fintype.v @@ -1300,7 +1300,9 @@ Qed. Lemma leq_card : #|T| <= #|T'|. Proof. exact: (leq_card_in (in2W _)). Qed. -Hypothesis card_range : #|T| = #|T'|. +Hypothesis card_range : #|T| >= #|T'|. + +Let eq_card : #|T| = #|T'|. Proof. by apply/eqP; rewrite eqn_leq leq_card. Qed. Lemma inj_card_onto y : y \in codom f. Proof. by move: y; apply/subset_cardP; rewrite ?card_codom ?subset_predT. Qed. |