Big operators for NatAntidiagonal
#
This file contains theorems relevant to big operators over Finset.NatAntidiagonal
.
theorem
Finset.Nat.sum_antidiagonal_swap
{M : Type u_1}
[AddCommMonoid M]
{n : ℕ}
{f : ℕ × ℕ → M}
:
((Finset.antidiagonal n).sum fun (p : ℕ × ℕ) => f p.swap) = (Finset.antidiagonal n).sum fun (p : ℕ × ℕ) => f p
theorem
Finset.Nat.prod_antidiagonal_swap
{M : Type u_1}
[CommMonoid M]
{n : ℕ}
{f : ℕ × ℕ → M}
:
((Finset.antidiagonal n).prod fun (p : ℕ × ℕ) => f p.swap) = (Finset.antidiagonal n).prod fun (p : ℕ × ℕ) => f p
theorem
Finset.Nat.sum_antidiagonal_subst
{M : Type u_1}
[AddCommMonoid M]
{n : ℕ}
{f : ℕ × ℕ → ℕ → M}
:
((Finset.antidiagonal n).sum fun (p : ℕ × ℕ) => f p n) = (Finset.antidiagonal n).sum fun (p : ℕ × ℕ) => f p (p.1 + p.2)
theorem
Finset.Nat.prod_antidiagonal_subst
{M : Type u_1}
[CommMonoid M]
{n : ℕ}
{f : ℕ × ℕ → ℕ → M}
:
((Finset.antidiagonal n).prod fun (p : ℕ × ℕ) => f p n) = (Finset.antidiagonal n).prod fun (p : ℕ × ℕ) => f p (p.1 + p.2)
theorem
Finset.Nat.sum_antidiagonal_eq_sum_range_succ_mk
{M : Type u_3}
[AddCommMonoid M]
(f : ℕ × ℕ → M)
(n : ℕ)
:
((Finset.antidiagonal n).sum fun (ij : ℕ × ℕ) => f ij) = (Finset.range n.succ).sum fun (k : ℕ) => f (k, n - k)
theorem
Finset.Nat.prod_antidiagonal_eq_prod_range_succ_mk
{M : Type u_3}
[CommMonoid M]
(f : ℕ × ℕ → M)
(n : ℕ)
:
((Finset.antidiagonal n).prod fun (ij : ℕ × ℕ) => f ij) = (Finset.range n.succ).prod fun (k : ℕ) => f (k, n - k)
theorem
Finset.Nat.sum_antidiagonal_eq_sum_range_succ
{M : Type u_3}
[AddCommMonoid M]
(f : ℕ → ℕ → M)
(n : ℕ)
:
((Finset.antidiagonal n).sum fun (ij : ℕ × ℕ) => f ij.1 ij.2) = (Finset.range n.succ).sum fun (k : ℕ) => f k (n - k)
This lemma matches more generally than
Finset.Nat.sum_antidiagonal_eq_sum_range_succ_mk
when using rw ←
.
theorem
Finset.Nat.prod_antidiagonal_eq_prod_range_succ
{M : Type u_3}
[CommMonoid M]
(f : ℕ → ℕ → M)
(n : ℕ)
:
((Finset.antidiagonal n).prod fun (ij : ℕ × ℕ) => f ij.1 ij.2) = (Finset.range n.succ).prod fun (k : ℕ) => f k (n - k)
This lemma matches more generally than Finset.Nat.prod_antidiagonal_eq_prod_range_succ_mk
when
using rw ←
.