grad

Attested. A fixture written in AXON is compiled and executed by a gate in the test suite, so this page describes behaviour a test exercises.

Since v2.65.0 · Used inside a declaration

Grammar

let g = grad(<expr>, <wrt-binding>)

grad is the proof-carrying derivative: symbolic differentiation over the v2.26.0 expression language, at COMPILE time.

What the runtime actually does (v2.65.0)

The gradient is IR: differentiation happens in the frontend, the derivative expression ships inside the artifact under the PCC GradientSoundness witness, and the runtime only evaluates it — zero tokens, no model in the loop, no numeric approximation.

Proof

axon-rs/tests/grad_runtime.rs + axon-frontend/tests/grad_grammar.rs.

See also

• axon://primitives/compute — the sibling: named pure functions over the same expression language.