English
The sum over a finite set of weighted homogeneous polynomials of degree n is weighted homogeneous of degree n.
Русский
Сумма по конечному индексу взвешенно однородных по степени n полиномов сохраняет степень n.
LaTeX
$$s.sum (fun i => φ i) has degree n if each φ i has degree n$$
Lean4
/-- The sum of weighted homogeneous polynomials of degree `n` is weighted homogeneous of
weighted degree `n`. -/
theorem sum {ι : Type*} (s : Finset ι) (φ : ι → MvPolynomial σ R) (n : M) {w : σ → M}
(h : ∀ i ∈ s, IsWeightedHomogeneous w (φ i) n) : IsWeightedHomogeneous w (∑ i ∈ s, φ i) n :=
(weightedHomogeneousSubmodule R w n).sum_mem h