//! Binary (two-component) staged-separation methods — rungs 1–2 of the
//! pedagogical ladder (PLAN §4).
//!
//! Everything in this module works on the **light component's** mole
//! fraction: `x` in the liquid, `y` in the vapor, with the more volatile
//! component listed first. This is the classical McCabe–Thiele convention
//! (Seader, Henley & Roper, *Separation Process Principles*, Ch. 7).
pub use ;
pub use ;
pub use ;