English
For a ∈ ℕ and b ∈ ℕ with b ≠ 0, the division of naturals corresponds to the division in α after casting: (divNat a b)° = (a/b)° in α.
Русский
Для a ∈ ℕ и b ∈ ℕ с b ≠ 0, частное деления натуралов совпадает с частным деления после приведения в α: (divNat a b)° = (a/b)°.
LaTeX
$$$ (\operatorname{divNat} a b)^{\uparrow} = (a / b)^{\uparrow} $$$
Lean4
@[simp]
theorem cast_divNat (a b : ℕ) : (divNat a b : α) = a / b :=
by
rw [← cast_natCast, ← cast_natCast b, ← cast_div]
congr
ext
apply Rat.mkRat_eq_div