formalize

formalize is a command for coding agents from frenzymath/Archon. It costs 11 tokens per session (2,459 once invoked), scanned A, original, Apache-2.0.

An interactive Lean 4 command that turns informal mathematical claims into checked declaration outlines and guides attempts to prove them. Lean 4 is a programming language and proof checker for formal mathematics.

In plain words
What is it for?
Use it to formalize claims from text or PDFs, choose a proof rigor level, generate Lean files, and work through guided proving cycles.
Why use it?
It connects theorem drafting and proof work in one guided process, so you can move from an idea to a checked formal statement.

Command

Part of the lean4 plugin — 1 skill, 11 commands, 4 agents, 3 hooks shipped together

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 commands/frenzymath/archon/formalize
Clone the repo
git clone --depth 1 https://github.com/frenzymath/Archon

Or install lean4, the plugin that ships this one along with the rest of its 1 skill, 11 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.

agentmods badge for formalize

README.md
[![agentmods](https://agentmods.dev/badge/commands/frenzymath/archon/formalize.svg)](https://agentmods.dev/commands/frenzymath/archon/formalize)
Your own site
<a href="https://agentmods.dev/commands/frenzymath/archon/formalize"><img src="https://agentmods.dev/badge/commands/frenzymath/archon/formalize.svg" alt="Measured on agentmods" height="20"></a>
Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,459 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.

ModelPer sessionOnce invoked
Fable 5 $0.00011 $0.02459
Opus 5 $0.00005 $0.01229
Sonnet 5 $0.00002 $0.00492
Haiku 4.5 $0.00001 $0.00246

Measured 4d ago against content hash 7743507e6664, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

formalize 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 4d ago.

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.

src/archon/.archon-src/skills/lean4/commands/formalize.md · 163 lines

How it starts

The opening of the file, as written. The whole thing — 163 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Lean4 Formalize

Interactive formalization: draft Lean skeletons from informal claims, then prove them with guided cycles. Combines /lean4:draft and /lean4:prove in a single human-in-the-loop workflow.

Compatibility: Accepts all flags from old formalize (v4.3.x). Semantics are broader — new formalize runs a full prove cycle after drafting. Users wanting the old lighter-weight "draft + shallow proof attempt" behavior should use /lean4:draft --mode=attempt. Users wanting skeletons only should use /lean4:draft.

Usage

/lean4:formalize "Every continuous function on a compact set is bounded"
/lean4:formalize --rigor=axiomatic "Zorn's lemma implies AC"
/lean4:formalize --source ./paper.pdf          # Ingest, pick claims, formalize
/lean4:formalize --source ./paper.pdf "Theorem 3.2"  # Source as context, topic as claim
/lean4:formalize --output=file --out=MyTheorem.lean "..."

Inputs

Arg Required Default Description
topic no Informal claim to formalize. Optional when --source provides it (source-led flow). At least one of topic or --source must be given; omitting both is a hard error.
--rigor no checked checked | sketch | axiomatic
--verify no best-effort best-effort | strict. Verification strictness for key claims. See learn-pathways.md.
--level no intermediate beginner | intermediate | expert
--output no chat chat | scratch | file
--out no Output path. Required when --output=file; hard error if missing.
--overwrite no false Allow overwriting existing files with --output=file. Without flag, existing target → hard error.
--source no File path, URL, or PDF to seed formalization. See learn-pathways.md.
--intent no math auto | usage | math. See learn-pathways.md.
--presentation no auto informal | supporting | formal | auto. Controls user-facing display, not Lean backing. See learn-pathways.md.
--claim-select no first | named:"..." | regex:"...". Noninteractive claim selection from --source.
--draft-mode no attempt skeleton | attempt. Mode for the draft phase (default is attempt in formalize context).
--draft-elab-check no best-effort best-effort | strict. Elaboration check for the draft phase.
--deep no never never | ask | stuck | always. Deep mode for prove phase.
--deep-sorry-budget no 1 Max sorries per deep invocation
--deep-time-budget no 10m Max time per deep invocation
--commit no ask ask | auto | never
--golf no prompt prompt | auto | never

Read the full file on GitHub · 163 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.

  1. 4d ago First seen · 163 lines · 11 tokens per session scan A 7743507e6664

Subscribe to this mod's changes

formalize is a command published in the GitHub repository frenzymath/Archon (213 stars, last pushed 17d ago), licensed Apache-2.0. It adds 11 tokens to every session and 2,459 once invoked, about $0.0001 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.