English
For [NeZero n], (a.valMinAbs.natAbs : ZMod n) equals if a.val ≤ n/2 then a else -a.
Русский
Для [NeZero n], (a.valMinAbs.natAbs : ZMod n) равно если a.val ≤ n/2 то a иначе -a.
LaTeX
$$$[\\mathrm{NeZero}\\ n]\\ (a : \\mathbb{Z}/n\\mathbb{Z}).valMinAbs.natAbs = \\text{if } a.val \\le \\frac{n}{2} \\text{ then } a \\text{ else } -a$$$
Lean4
theorem valMinAbs_natAbs_eq_min [hpos : NeZero n] (a : ZMod n) : a.valMinAbs.natAbs = min a.val (n - a.val) :=
by
rw [valMinAbs_def_pos]
have := a.val_lt
omega