AlphaVerus

A model translates programs into Verus, tree search repairs them with verifier feedback, and a filter keeps trustworthy results as examples.

Read the paper

The loop

  1. Proposes

    Verus translations of programs (from Dafny) and repaired versions, from a Llama 3.1 70B model

  2. Judged by

    The Verus verifier, plus a filter that rejects translations whose specification or program is misaligned

  3. Steers

    Treefinement tree search fixes errors from verifier feedback; verified, filtered programs become prompt examples

Headline result

With Llama 3.1 70B and no model fine-tuning, verified-code generation reaches 32.9% on HumanEval-Verus and 65.7% on MBPP-verified (pass@256), versus 27.1% and 35.9% for GPT-4o and 11.8% and 26.9% for Llama 3.1 70B.

What this does not prove

HumanEval-Verus and MBPP-verified are small, hand-adapted benchmarks, and the task is generating code plus proofs from specifications. Verification proves code matches the specification, so the misalignment filter matters.

How it generalizes the harness

Verus judges validity, a tree of candidate repairs is searched, and a built-in filter guards against the model gaming the verifier.

Classification

Classification of AlphaVerus
What it proposesProgram
Generative modelLlama 3.1 70B (frozen, no fine-tuning)
Algorithmic authorityVerus verifier with a misalignment filter
FeedbackVerifier errors
What gets updatedPrompt context and search tree
When it runsAt inference time
ValidityFormal (machine-checked)
EvidenceExperiments reported
LineageOriginal system