//! Physics primitives for kinematic expressions, reaction channels, event
//! generation, histograms, and particle quantum numbers.
/// Validated axes and shared bin-assignment semantics.
/// Reaction-graph construction and frame-dependent kinematics.
/// Monte Carlo proposal primitives.
/// Weighted histogram utilities.
/// Weighted joint-histogram primitives.
/// Numeric and symbolic three- and four-vector types.
pub use ;