English
If f: X → n → R has sum a, then x ↦ diagonal(f(x)) has sum diagonal(a).
Русский
Если f: X → n→R имеет сумму a, то x ↦ diagonal(f(x)) имеет сумму diagonal(a).
LaTeX
$$$\\operatorname{HasSum}(f,a,L) \\Rightarrow \\operatorname{HasSum}(x \\mapsto \\operatorname{diagonal}(f(x)), \\operatorname{diagonal}(a), L)$$$
Lean4
theorem matrix_conjTranspose [StarAddMonoid R] [ContinuousStar R] {f : X → Matrix m n R} {a : Matrix m n R}
(hf : HasSum f a L) : HasSum (fun x => (f x)ᴴ) aᴴ L :=
(hf.map (Matrix.conjTransposeAddEquiv m n R) continuous_id.matrix_conjTranspose :)