English
In ENNReal, if 0 < b < a and c ≠ 0, then (a - b)/c = a/c - b/c.
Русский
В ENNReal, если 0 < b < a и c ≠ 0, то (a - b)/c = a/c - b/c.
LaTeX
$$$0 < b \implies b < a \implies c \neq 0 \Rightarrow \dfrac{a-b}{c} = \dfrac{a}{c} - \dfrac{b}{c}$$$
Lean4
protected theorem sub_div (h : 0 < b → b < a → c ≠ 0) : (a - b) / c = a / c - b / c :=
by
simp_rw [div_eq_mul_inv]
exact ENNReal.sub_mul (by simpa using h)