LEGO-Prover grows a reusable library of machine-checked lemmas during proof search

The system couples a prover and an evolver through a shared skill library. The prover constructs modular proofs from retrieved and newly generated lemmas, while the evolver transforms verified skills to increase their generality, reuse and complexity.

What happened?

LEGO-Prover decomposed miniF2F problems into subgoal lemmas, retrieved or generated reusable skills, verified them with Isabelle through PISA and accumulated more than 20,000 skills in a growing library; the paper reported a 57.0% pass rate on miniF2F-valid and gains from the newly added skills.

Why it matters

It provided an early concrete design for cumulative formal reasoning, where successful proof fragments become durable resources for future proof attempts rather than disappearing after a single theorem is solved.

Significance rationale: LEGO-Prover made a growing library of reusable, machine-checked lemmas part of the proving loop itself, moving beyond fixed theorem libraries and one-off proof trajectories toward accumulated formal skills that can support later problems.

Historical context

Primary evidence

Evidence & status at a glance

Significance
H2 · Field milestone
Verification
Paper released
Evidence level
E3 · Inspectable artifact
AI role
AI primary, human verified
Formal assurance
Artifact available

How should these labels be read? →

Contribution & verification

Mathematical novelty
Tooling only
Interface
Formal, Symbolic, Hybrid
AI contribution
Large language models proposed subgoal lemmas, proof blocks and skill transformations, while Isabelle mechanically checked formal code before skills were admitted to the reusable library.
Human contribution
Researchers designed the prover/evolver architecture, skill-library lifecycle, retrieval and prompting procedures, integrated PISA and Isabelle, and evaluated the system on miniF2F.
Verification
Paper released · E3 · Inspectable artifact · Artifact available
Last reviewed
2026-09-11

Technical details

Systems
lego-prover, isabelle, pisa
Organizations
—
Problems
minif2f
Methods
theorem-proving, growing-skill-library, lemma-generation, retrieval, modular-proof-construction

Sources & artifacts

Verification history

  • 2023-10-01 · Paper released · E2 · Research record

    The public research record introduced the growing verified-skill-library architecture and reported miniF2F evaluations.

  • 2026-09-11 · Paper released · E3 · Inspectable artifact

    The authors' public repository exposes the LEGO-Prover implementation, miniF2F integration and generated results. E3 records inspectability; it does not claim an independent replay of the reported experiments.

Corrections

No corrections recorded.