English
If IsCocomm holds for each A_i, then the Finsupp structure is IsCocomm.
Русский
Если справедливо IsCocomm для каждой A_i, то Finsupp обладает IsCocomm.
LaTeX
$$$\text{IsCocomm}_{R}(\iota \to A_i)$ under the appropriate Triple conditions.$$
Lean4
instance instIsCocomm [IsCocomm R A] : IsCocomm R (ι →₀ A) where
comm_comp_comul :=
by
ext i : 1
-- TODO: Add `reassoc` for `LinearMap`. Then we wouldn't need to reassociate back and forth.
simp only [comp_assoc, comul_comp_lsingle]
simp only [← comp_assoc, ← TensorProduct.map_comp_comm_eq]
simp [LinearMap.comp_assoc]