Math Proof
Write proofs suitable for a paper draft. The deliverable is a complete proof, not an outline. Every transition must be checkable by a skeptical reader without filling in missing algebra, sign arguments, or quantifier choices.
This skill adapts Moran Koren's Theorist Toolbox proof discipline for Codex. Preserve the core invariant: if a step is not proved, cited, or explicitly marked as conjectural, do not present it as established.
Workflow
- Parse the exact claim, hypotheses, domains, and conclusion.
- State the proof plan before proving: direct proof, contradiction, induction, fixed point, comparative statics, counterexample search, or case split.
- Define all notation before use. Give object types and parameter domains.
- Prove one numbered step at a time. Each step must open with what it will show.
- Show intermediate algebra. Do not jump from setup to simplified result.
- Sign every derivative, inequality, monotonicity claim, and limit claim at the line where it appears.
- Handle edge cases and boundary behavior explicitly.
- Separate proved results from conjectures, examples, and numerical evidence.
- End with a short intuition paragraph when useful, then close the proof with
\square.
Proof Discipline
- Use
\triangleqfor definitions and=for equalities. - Use display math for multi-term expressions, ratios, derivatives, thresholds, and relation chains.
- Before algebra, say the goal: "It remains to show that ...".
- When differentiating a ratio, compute numerator and denominator derivatives before applying the quotient rule.
- When manipulating inequalities, state why the inequality direction is preserved or reversed.
- If a threshold is integer-valued but differentiated as continuous, flag the relaxation and explain how discreteness affects the claim.
- When invoking a theorem, instantiate it in the paper's notation. If the theorem is not standard, cite it precisely or prove the needed lemma.
- Never prove the general case by checking examples. Examples are evidence, not proof.
Banned Moves
Do not use these phrases or their equivalents unless immediately followed by the missing argument:
- clearly
- obviously
- it is easy to see
- straightforward
- by a similar argument
- omitted for brevity
- this dominates that
- the sign is apparent
If the proof relies on a plausible but unproved claim, write it as a conjecture or open obligation. Do not camouflage it as intuition.
Output Format
Use Markdown with LaTeX math.
Recommended structure:
markdown## Setup Define primitives, notation, assumptions, and the exact claim. ## Proof ### Step 1: <goal of the step> ... ### Step 2: <goal of the step> ... The intuition is ... \(\square\)
If the requested proof cannot be completed, return:
- the strongest partial result proved,
- the exact unproved step or obstruction,
- any counterexample or parameter region found,
- what would be needed to close the gap.


