What is proof-golfer?

A Lean 4 proof editor that shortens and clarifies proofs after they already compile. Lean 4 is a programming language and proof checker for precise mathematics.

Use it to look for shorter or more direct proof patterns, safely simplify local bindings, and verify each change in a Lean file.

It helps remove unnecessary steps while preserving what the proof means. It checks that proposed changes remain valid.

proof-golfer — Agent for coding agents by cameronfreer: A Lean 4 proof editor that shortens and clarifies…

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add agents/cameronfreer/lean4-skills/proof-golfer

Clone the repo

git clone --depth 1 https://github.com/cameronfreer/lean4-skills

Or install lean4, the plugin that ships this one along with the rest of its 1 skill, 12 commands, 4 agents, 3 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/agents/cameronfreer/lean4-skills/proof-golfer.svg)](https://agentmods.dev/agents/cameronfreer/lean4-skills/proof-golfer)

Your own site

<a href="https://agentmods.dev/agents/cameronfreer/lean4-skills/proof-golfer"><img src="https://agentmods.dev/badge/agents/cameronfreer/lean4-skills/proof-golfer.svg" alt="Measured on agentmods" height="20"></a>

Per session 45 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 2,505 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00045	$0.02505
Opus 5	$0.00023	$0.01252
Sonnet 5	$0.00009	$0.00501
Haiku 4.5	$0.00005	$0.00250

Measured yesterday against content hash cde6ab72b2e6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

proof-golfer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/lean4/agents/proof-golfer.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Inputs

Consume the run-contract/v1 dispatch record (record == "dispatch"): read target, the context envelope, and owned_files + file_baseline (fail closed — see below). Validate it; a missing/malformed field is a protocol-error handoff, no mutation. A passing build is required (verify before starting).

parameters shape for this worker: {search_mode: "off" | "quick" | "full", golfable_patterns: [...], candidate_targets: [...]} (default search_mode quick).

Actions

MCP canary runs before step 3 (after pure-script steps 1-2). See step 2 for details and fallback behavior.

Find patterns (in policy order: directness → structural → conditional) with false-positive filtering:
```
lean4-skills-find-golfable FILE.lean --filter-false-positives
```
For direct-proof discovery when search_mode ≠ off or syntactic pass stalls:
```
lean4-skills-find-exact-candidates FILE.lean
```
Verify safety before inlining any binding:
```
lean4-skills-analyze-let-usage FILE.lean --line LINE
```
- 1-2 uses: Safe to inline
- 3-4 uses: Check carefully (40% worth optimizing)
- 5+ uses: NEVER inline
MCP canary: Before step 3, test lean_diagnostic_messages(file). If unavailable (tool-not-found, missing from context, or inaccessible), emit "⚠ Lean MCP tools unavailable — golfing limited to syntactic patterns", skip steps 3-4 (require lean_multi_attempt), and reduce step 5 to max 1 hunk with lake env lean <file> (from project root) per-hunk verification; reserve lake build for final verification only.

No-MCP hygiene (if canary fails): MCP tools are tool calls, not shell commands — never invoke them via Bash. Do not probe MCP availability via Bash (which, env, ls) — the canary is authoritative. Stop retrying MCP for this run. Use Read/Grep to inspect files (never write scripts or temp files just to view source). Start from pre-collected context in the parent prompt.

Read the full file on GitHub · 161 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

yesterday Changed · +2 lines cde6ab72b2e6
6d ago First seen · 159 lines · 45 tokens per session scan A ed1361322d2e

Subscribe to this mod's changes

proof-golfer is an agent published in the GitHub repository cameronfreer/lean4-skills (430 stars, last pushed yesterday), licensed MIT. It adds 45 tokens to every session and 2,505 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Scientific

editor

Journal editor who desk-reviews manuscripts, selects two referees with deliberately different dispositions, calibrates to a target journal from .claude/references/journal-profiles.md, and synthesizes an editorial decision (FATAL / ADDRESSABLE / TASTE). Used by /review-paper --peer [journal].

pedrohcgs/claude-code-my-workflow · 64 tokens

Geoprocessing Specialist

ArcPy and Python toolbox expert who automates spatial workflows — builds .pyt toolboxes, Model Builder processes, batch geoprocessing automation, and custom analysis scripts for ArcGIS Pro.

SHAdd0WTAka/Zen-Ai-Pentest · 45 tokens

research-scout

Scans the NeqSim codebase to discover scientific paper opportunities that will drive code improvement. Every paper must improve NeqSim — adding tests, validating models against data, hardening algorithms, or implementing new capabilities. Produces ranked, actionable topics that feed into the planner agent.

equinor/neqsim · 61 tokens

algorithm-expert

RL algorithm expert. Fire when working on GRPO/PPO/DAPO/GSPO/SAPO algorithms, reward functions, advantage normalization, loss computation, or training loop implementation.

redai-infra/Relax · 37 tokens

mathodology-problem-analyst

Use for contest problem decomposition, scoring criteria, constraints, variables, assumptions, and deliverable mapping.

sweetcornna/mathodology · 29 tokens

astronomical-instrumentation-scientist

Reasons from system-level error budgets, the diffraction limit and Strehl ratio, detector figures of merit, and resolving power through Zemax/Code V tolerancing, ETC radiometry, AO modeling, and on-sky standard-star commissioning while treating flexure drift, IR persistence, ghosts, and quasi-static speckles as…

K-Dense-AI/scientific-agents · 78 tokens