diff options
Diffstat (limited to 'mathcomp/fingroup')
| -rw-r--r-- | mathcomp/fingroup/perm.v | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mathcomp/fingroup/perm.v b/mathcomp/fingroup/perm.v index ebd4230..5775e34 100644 --- a/mathcomp/fingroup/perm.v +++ b/mathcomp/fingroup/perm.v @@ -640,6 +640,9 @@ Proof. by move=> g; apply/permP; case. Qed. Lemma permS1 : all_equal_to (1 : 'S_1). Proof. by move=> g; apply/permP => i; rewrite !ord1. Qed. +Lemma permS01 n : n <= 1 -> all_equal_to (1 : 'S_n). +Proof. by case: n => [|[|]//=] _ g; rewrite (permS0, permS1). Qed. + Section CastSn. Definition cast_perm m n (eq_mn : m = n) (s : 'S_m) := |