代数 - 環

\((X, 0, \pm)\) に積と割り算を足して出来る \((X, 0, 1, \pm, \times, \div)\) のこと.

/// Algebra - Ring
// @algebra.group.rs
trait Ring: Group + std::ops::Mul<Output=Self> + std::ops::Div<Output=Self> {
    fn one() -> Self;
}
impl Ring for i32 { fn one() -> Self { 1 }}
impl Ring for i64 { fn one() -> Self { 1 }}
impl Ring for f32 { fn one() -> Self { 1.0 }}
impl Ring for f64 { fn one() -> Self { 1.0 }}