English
The identity is the neutral element for the composition of order isomorphisms: refl trans f = f.
Русский
Тождественный изоморфизм порядка является нейтральным элементом при композиции: refl.trans f = f.
LaTeX
$$$\text{refl} : α \too α$, $(\text{refl } α) \trans f = f$.$$
Lean4
/-- The identity map as an ordered monoid isomorphism. -/
@[to_additive /-- The identity map as an ordered additive monoid isomorphism. -/
]
protected def refl : α ≃*o α :=
{ MulEquiv.refl α with map_le_map_iff' := by simp }