DOC: Doc for ImplicitODE
//! * `ExMethod` : Explicit method
//! * `Euler` : Euler first order
//! * `RK4` : Runge Kutta 4th order
-//! * `ImMethod` : Implicit method **(to be implemented)**
-//! * `BDF` : Backward Euler 1st order
+//! * `ImMethod` : Implicit method
+//! * `BDF` : Backward Euler 1st order (To be fixed)
//! * `GL4` : Gauss Legendre 4th order
//! * `Environment` : External environment (CubicSpline, Vec<f64>, Matrix or Another external table)
//!
//! * `to_use` : Just check whether information is enough
//! * `env` : Environment
//!
+//! # `ImplicitODE` struct
+//!
+//! `ImplicitODE` is struct to solve stiff ODE with implicit methods.
+//!
+//! ```no_run
+//! extern crate peroxide;
+//! use std::collections::HashMap;
+//! use peroxide::fuga::{State, ImMethod, BoundaryCondition, ODEOptions, Environment, AD};
+//!
+//! #[derive(Clone)]
+//! pub struct ImplicitODE<E: Environment> {
+//! state: State<AD>,
+//! func: fn(&mut State<AD>, &E),
+//! step_size: f64,
+//! method: ImMethod,
+//! init_cond: State<AD>,
+//! bound_cond1: (State<AD>, BoundaryCondition),
+//! bound_cond2: (State<AD>, BoundaryCondition),
+//! stop_cond: fn(&Self) -> bool,
+//! times: usize,
+//! to_use: HashMap<ODEOptions, bool>,
+//! env: E,
+//! }
+//! ```
+//!
//! ## Example
//!
//! ### Lorenz Butterfly
