Proof Writer Skill for Claude

Proof Write: Rigorous Theorem / Lemma Drafting

Write a mathematically honest proof package, not a polished fake proof.

Constants

• DEFAULT_PROOF_DOC = PROOF_PACKAGE.md in project root
• STATUS = PROVABLE AS STATED | PROVABLE AFTER WEAKENING / EXTRA ASSUMPTION | NOT CURRENTLY JUSTIFIED

Context: $ARGUMENTS

Goal

Produce exactly one of:

• a complete proof of the original claim
• a corrected claim plus a proof of the corrected claim
• a blockage report explaining why the claim is not currently justified

Inputs

Extract and normalize:

• exact theorem / lemma / proposition / corollary statement
• explicit assumptions
• notation and definitions
• any user-provided proof sketch, partial proof, or intended strategy
• nearby lemmas or claims in local notes, appendix files, or theorem drafts if the request points to them
• desired output style if specified: concise, appendix-ready, or full-detail

If notation or assumptions are ambiguous, state the exact interpretation you are using before proving anything.

Workflow

Step 1: Gather Proof Context

Determine the target proof file with this priority:

• a file path explicitly specified by the user
• a proof draft already referenced in local notes or theorem files
• PROOF_PACKAGE.md in project root as the default target

Read the relevant local context:

• the chosen target proof file, if it already exists
• theorem notes, appendix drafts, or files explicitly mentioned by the user

Extract:

• exact claim
• assumptions
• notation
• proof sketch or partial proof
• nearby lemmas that the draft may depend on

Step 2: Normalize the Claim

Restate:

• the exact claim being proved
• all assumptions, separately from conclusions
• all symbols used in the claim

Identify:

• hidden assumptions
• undefined notation
• scope ambiguities
• whether the available sketch proves the full claim or only a weaker variant

Preserve the user's original theorem statement unless a change is explicitly required.

If you use a stronger normalization or cleaner internal formulation only to make the proof easier, keep that as an internal proof device rather than silently replacing the original claim.

Step 3: Feasibility Triage

Before writing a proof, classify the claim into exactly one status:

• PROVABLE AS STATED
• PROVABLE AFTER WEAKENING / EXTRA ASSUMPTION
• NOT CURRENTLY JUSTIFIED

Check explicitly:

• does the conclusion actually follow from the listed assumptions?
• is any cited theorem being used outside its conditions?
• is the claim stronger than what the available argument supports?
• is there an obvious counterexample, boundary case, or quantifier failure?

If the claim is not provable as stated, do NOT fabricate a proof.

Do NOT silently strengthen assumptions or narrow the theorem's scope just to make the proof work.

Step 4: Build a Dependency Map

Choose a proof strategy, for example:

• direct
• contradiction
• induction
• construction
• reduction to a known result
• coupling / probabilistic argument
• optimization inequality chaining

Then write a dependency map:

• main claim
• required intermediate lemmas
• named theorems or inequalities that will be cited
• which assumptions each nontrivial step depends on
• boundary cases that must be handled separately

If one step is substantial, isolate it as a lemma instead of burying it in one sentence.

Step 5: Write the Proof Document

Write to the chosen target proof file.

If the target proof file already exists:

• read it first
• update the relevant claim section
• do not blindly duplicate prior content

If the user does not specify a target, default to PROOF_PACKAGE.md in project root.

Do NOT write directly into paper sections or appendix .tex files unless the user explicitly asks for that target.

The proof package must include:

• exact claim
• explicit assumptions
• proof status
• announced strategy
• dependency map
• numbered major steps
• justification for every nontrivial implication

Mathematical rigor requirements:

• never use "clearly", "obviously", "it can be shown", "by standard arguments", or "similarly" to hide a gap
• define every constant and symbol before use
• check quantifier order carefully
• handle degenerate and boundary cases explicitly, or state why they are excluded
• if invoking a standard fact, state its name and why its assumptions are satisfied here
• use $...$ for inline math and $$...$$ for display equations
• never write math in plain text
• if the proof uses an equivalent normalization that is stronger in appearance than the user's original theorem statement, label it explicitly as a proof device and keep the original claim separate

Step 6: Final Verification

Before finishing the target proof file, verify:

• the theorem statement exactly matches what was actually shown
• every assumption used is stated
• every nontrivial implication is justified
• every inequality direction is correct
• every cited result is applicable under the stated assumptions
• edge cases are handled or explicitly excluded
• no hidden dependence on an unproved lemma remains

If a key step still cannot be justified, downgrade the status and write a blockage report instead of forcing a proof.

Required File Structure

Write the target proof file using this structure:

# Proof Package

## Claim
[exact statement]

## Status
PROVABLE AS STATED / PROVABLE AFTER WEAKENING / NOT CURRENTLY JUSTIFIED

## Assumptions
- ...

## Notation
- ...

## Proof Strategy
[chosen approach and why]

## Dependency Map
1. Main claim depends on ...
2. Lemma A depends on ...
3. Step k uses ...

## Proof
Step 1. ...
Step 2. ...
...
Therefore the claim follows. ∎

## Corrections or Missing Assumptions
- [only if needed]

## Open Risks
- [remaining fragile points, if any]

Output Modes

If the claim is provable as stated

Write the full file structure above with a complete proof.

If the original claim is too strong

Write:

• why the original statement is not justified
• the corrected claim
• the minimal extra assumption if one exists
• a proof of the corrected claim

If the proof cannot be completed honestly

Write:

• Status: NOT CURRENTLY JUSTIFIED
• the exact blocker: missing lemma, invalid implication, hidden assumption, or counterexample direction
• what extra assumption, lemma, or derivation would be needed to finish the proof
• a corrected weaker statement if one is available

Chat Response

After writing the target proof file, respond briefly with:

• status
• whether the original claim survived unchanged
• what file was updated

Key Rules

• Never fabricate a missing proof step.
• Prefer weakening the claim over overclaiming.
• Separate assumptions, derived facts, heuristics, and conjectures.
• Preserve the user's original theorem statement unless you explicitly mark a corrected claim or an internal normalization.
• If the statement is false as written, say so explicitly and give a counterexample or repaired statement.
• If uncertainty remains, mark it explicitly in Open Risks; do not hide it inside polished prose.
• Correctness matters more than brevity.