Add missing bound of `Real`
//! }
//! ```
-use std::ops::{Add, Div, Mul, Sub};
+use std::ops::{Add, Div, Mul, Sub, Neg};
use structure::dual::Dual;
use structure::hyper_dual::HyperDual;
@@ -62,6 +62,8 @@ pub trait Real:
PowOps
+ TrigOps
+ ExpLogOps
+ + Neg
+ + PartialOrd
+ Add<Output = Self>
+ Mul<Output = Self>
+ Div<Output = Self>
