English
The inverse of the canonical finsupp unique equivalence at d is the singleton at the unit: AddEquiv.finsuppUnique.symm d = single () d.
Русский
Обратное к каноническому едваёжному соответствию finsuppUnique равно одиночной функции на единице: AddEquiv.finsuppUnique.symm d = single () d.
LaTeX
$$$AddEquiv.finsuppUnique.symm\\; d = \\mathrm{single}\\;()\\;d$$$
Lean4
theorem _root_.AddEquiv.finsuppUnique_symm {M : Type*} [AddZeroClass M] (d : M) :
AddEquiv.finsuppUnique.symm d = single () d :=
by
rw [Finsupp.unique_single (AddEquiv.finsuppUnique.symm d), Finsupp.unique_single_eq_iff]
simp [AddEquiv.finsuppUnique]