English
The negative part a⁻ᵐ is defined as a⁻¹ ⊔ 1 in a lattice ordered group.
Русский
Отрицательная часть a⁻ᵐ определяется как a⁻¹ ⊔ 1 в решётке упорядоченной группы.
LaTeX
$$$a^{-\!\mathrm{m}} = a^{-1} \vee 1$$$
Lean4
/-- The *positive part* of an element `a` in a lattice ordered group is `a ⊔ 1`, denoted `a⁺ᵐ`. -/
@[to_additive /-- The *positive part* of an element `a` in a lattice ordered group is `a ⊔ 0`, denoted `a⁺`. -/
]
instance instOneLePart : OneLePart α where oneLePart a := a ⊔ 1