|
From mathcomp Require Import all_ssreflect all_algebra.
|
|
|
|
Lemma sum_odd_3: \sum_(0 <= i < 3.*2 | odd i) i = 3^2.
|
|
Proof. by rewrite unlock /=. Qed.
|
|
|
|
|
|
Lemma sum_nat_const_I3 n : \sum_(i in 'I_3) n = #|'I_3| * n.
|
|
Proof.
|
|
rewrite big_const.
|
|
rewrite iter_addn_0.
|
|
by rewrite mulnC.
|
|
Qed.
|