//! # Models Module
//!
//! Contains all set implementation types.
//!
//! This module provides concrete implementations of mathematical sets:
//! - `CustomSet`: Mutable set with full operation support
//! - `FrozenSet`: Immutable, thread-safe set
//! - `MultiSet`: Set allowing duplicate elements with multiplicity
pub use CustomSet;
pub use FrozenSet;
pub use MultiSet;