English
The zero element is the canonical image of zero under the embedding into the localization; the construction identifies zero with the ratio 0/1.
Русский
Ноль в RatFunc идентифицируется как отношение 0/1 в локализации.
LaTeX
$$$0_{\mathrm{RatFunc}(K)} = \frac{0}{1}$$$
Lean4
theorem zero_def : eta_helper Eq✝ @zero.{} @(delta% @definition✝) :=
by
intros
delta zero
rw [show wrapped✝ = ⟨@definition✝.{}, rfl✝⟩ from Subtype.ext✝ wrapped✝.2.symm✝]
rfl