//! Loop
use ;
/// A quasigroup with an unique identity element.
///
/// $\exists e \in \mathbb{Q}, \forall a \in \mathbb{Q}, \exists r, l \in
/// \mathbb{Q}$ such that $l ∘ a = a ∘ r = e $ The left inverse $r$ and
/// right inverse $l$ are not required to be equal. The following property is
/// added to the quasigroup structure:
///
/// This property follows from
///
/// $\forall a \in \mathbb{Q}, \exists e \in \mathbb{Q}$, such that $e ∘ a =
/// a ∘ e = a$.
;
impl_loop!;
impl_loop!;