English
The dfinsuppFamily of a composition with a left-constructed linear map equals the composition with the left linear map and f p, i.e. the two ways of wiring the inputs agree.
Русский
DFinsuppFamily композиции с лево-сконструированной линейной картой равна композиции с левой линейной картой и f p, то есть оба способа подачи входов совпадают.
LaTeX
$$$(\dfinsuppFamily f).compLinearMap (\lambda i => \DFinsupp.lsingle (p i)) = (\DFinsupp.lsingle p).compMultilinearMap (f p).$$$
Lean4
theorem dfinsuppFamily_single_left [∀ i, DecidableEq (κ i)] (p : Π i, κ i)
(f : MultilinearMap R (fun i ↦ M i (p i)) (N p)) :
dfinsuppFamily (Pi.single p f) =
(DFinsupp.lsingle p).compMultilinearMap (f.compLinearMap fun i => DFinsupp.lapply (p i)) :=
ext <| dfinsuppFamily_single_left_apply _ _