Crate oxieml 

OxiEML — All elementary functions from a single binary operator.

This crate implements the EML operator eml(x, y) = exp(x) - ln(y) and builds uniform binary trees that represent all elementary functions using only this operator and the constant 1.

Based on the paper: “All elementary functions from a single binary operator” (arXiv:2603.21852).

Capabilities

1. Symbolic Regression: Discover closed-form formulas from data via gradient-based search over EML tree topologies.
2. Uniform Tree Representation: Express any elementary function using the grammar S → 1 | eml(S, S).

Example

use oxieml::{EmlTree, Canonical, EvalCtx};

// Build exp(x) = eml(x, 1)
let x = EmlTree::var(0);
let exp_x = Canonical::exp(&x);

// Evaluate at x = 1.0
let ctx = EvalCtx::new(&[1.0]);
let result = exp_x.eval_real(&ctx).unwrap();
assert!((result - std::f64::consts::E).abs() < 1e-10);

Re-exports

pub use canonical::Canonical;

pub use error::EmlError;

pub use eval::EvalCtx;

pub use lower::LoweredOp;

pub use lower_interval::IntervalLO;

pub use named_const::NamedConst;

pub use parser::ParseError;

pub use parser::parse;

pub use solve::SolveResult;

pub use symreg::SymRegLoss;

pub use symreg::DiscoveredFormula;

pub use symreg::MultiOutputStrategy;

pub use symreg::SymRegConfig;

pub use symreg::SymRegEngine;

pub use symreg::SymRegStrategy;

pub use symreg::pareto_front;

pub use tree::EmlNode;

pub use tree::EmlTree;

pub use units::UnitError;

pub use units::Units;

Modules

canonical

Canonical EML tree constructions for elementary functions.

compile

Compile EML trees to Rust source code.

error

Error types for the OxiEML crate.

eval

Numerical evaluation of EML trees.

grad

Automatic differentiation for EML trees.

lower

Lowering EML trees to standard mathematical operations.

lower_grad

Symbolic differentiation for the lowered IR.

lower_interval

Interval arithmetic for over-approximate evaluation of LoweredOp trees.

lower_simplify

Algebraic simplification for the lowered IR.

lower_units

Dimensional analysis extension for LoweredOp.

named_const

Named mathematical constants for the LoweredOp IR.

parser

Parser for EML expression notation.

simplify

EML tree simplification and normalization.

solve

Symbolic equation solving for LoweredOp expression trees.

symreg

Symbolic regression engine.

tree

EML tree data structures.

units

Dimensional analysis for unit-aware symbolic regression.