English
Right division by a nonzero a is a permutation with inverse x ↦ x a.
Русский
Правое деление на ненулевой a образует перестановку с обратной функцией x ↦ x a.
LaTeX
$$$a \\neq 0 \\Rightarrow \\text{Perm } (x \\mapsto x / a)$ with inverse $(x \\mapsto x a)$$$
Lean4
/-- Right division by a nonzero element in a `GroupWithZero` is a permutation of the
underlying type. -/
@[simps! +simpRhs]
def divRight₀ (a : G₀) (ha : a ≠ 0) : Perm G₀ where
toFun := (· / a)
invFun := (· * a)
left_inv _ := by simp [ha]
right_inv _ := by simp [ha]