numerical-check

numerical-check is a skill for Claude Code from flonat/flonat-research. It costs 65 tokens per session (2,185 once invoked), scanned A, original, MIT.

A computational check that tests a mathematical claim across many chosen or random parameter values to look for counterexamples. It provides evidence about whether the claim may hold, but not a proof.

In plain words
What is it for?
Use it to test claims about monotonicity, thresholds, inequalities, comparative statics, or limits.
Why use it?
It can reveal false assumptions or edge cases before you present an unproven result as true.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: names the AskUserQuestion tool; $skill-name invocation.

Good fit Use it to test claims about monotonicity, thresholds, inequalities, comparative statics, or limits.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/flonat/flonat-research/numerical-check
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.

Any agent
npx skills add flonat/flonat-research --skill numerical-check
Clone the repo
git clone --depth 1 https://github.com/flonat/flonat-research

Made for: Claude Code.

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 numerical-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/flonat/flonat-research/numerical-check/github.svg)](https://agentmods.dev/skills/flonat/flonat-research/numerical-check)
Your own site
<a href="https://agentmods.dev/skills/flonat/flonat-research/numerical-check"><img src="https://agentmods.dev/badge/skills/flonat/flonat-research/numerical-check/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for numerical-check

Your own site · 80×15
<a href="https://agentmods.dev/skills/flonat/flonat-research/numerical-check"><img src="https://agentmods.dev/badge/skills/flonat/flonat-research/numerical-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 65 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,185 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium analysis-evasion · line 1
    Suspicious Unicode normalization or mixed-script content
    Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
How audits are shown
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 5.1 $0.00065 $0.02185
Opus 5 $0.00032 $0.01092
Sonnet 5 $0.00013 $0.00437
Haiku 4.5 $0.00006 $0.00218

Measured 7d ago against content hash fbb2917118d5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

numerical-check 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 7d 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.

skills/numerical-check/SKILL.md · 134 lines

How it starts

The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Numerical Check: Falsify a Self-Authored Math Claim by Sweep

Empirically stress-test a mathematical claim you wrote but have not proven. The goal is falsification: throw many random instances at the claim and try to break it. A single genuine counterexample kills the claim; a large clean sweep is evidence, never proof.

When to Use

  • You wrote a Proposition / Theorem / Conjecture (monotonicity, threshold, comparative-static, inequality, closed-form, limit) and want to know if it's actually true before claiming it.
  • numerical-check, "stress-test my conjecture", "find a counterexample to X", "is Q(ρ) really monotone", "does the threshold hold for all …".
  • The write-time empirical arm of the mark-unverified rule (self-authored math must be checked before assertion).

When NOT to Use

Situation Use instead
Verify an algebra / derivative / limit / closed-form identity symbolic-check (R2)
Machine-prove a lemma (want a proof, not a stress-test) lean-check (R3)
Re-verify a computed empirical result in another language cross-language-check
Conceptual / assumption-completeness review domain-reviewer (agent)

Position in the verification spectrum

R1 — numerical falsification. Can FALSIFY definitively (a confirmed counterexample refutes the claim) but can never VERIFY (no counterexample ≠ proof). The strongest positive result is INCONCLUSIVE (supported): no counterexample in N draws. Pair with lean-check (R3) to prove the claim once it survives.

Procedure

1. Formalize the claim as a predicate over a domain

Restate the claim as P(x) that must hold for all x in a domain D. Make the failure condition explicit and quantitative.

  • "Q(ρ) is monotone decreasing in ρ" → P(instance) := max_i (Q(ρ_{i+1}) − Q(ρ_i)) ≤ tol over a ρ-grid.
  • "threshold ρ* separates help/hurt" → P := (Q<p_max) iff (ρ>ρ*).
  • Write down the domain D precisely (which parameters, which ranges, which side-conditions — e.g. "mean competence > ½, dispersed").

Read the full file on GitHub · 134 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. 7d ago First seen · 134 lines · 65 tokens per session scan A fbb2917118d5

Subscribe to this mod's changes

numerical-check is a skill published in the GitHub repository flonat/flonat-research (133 stars, last pushed 16d ago), licensed MIT. It adds 65 tokens to every session and 2,185 once invoked, about $0.0003 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 2026-09-03.

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