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name: mathmodel-latex-skill description: Generate stable and competition-style LaTeX mathematical modeling paper projects for MCM/ICM and CUMCM. Use when Codex needs to create, adapt, compile, or preflight competition paper templates for COMAP MCM/ICM, Chinese Undergraduate Mathematical Contest in Modeling (CUMCM), or similar mathematical modeling submissions, including mcmthesis, cumcmthesis, XeLaTeX, latexmk, PDF page/size checks, identity-info checks, references, appendices, and AI-use disclosure sections.

Mathematical Modeling LaTeX Projects

Use this skill to create reproducible LaTeX paper projects for MCM/ICM and CUMCM. Prefer the templates in this skill, keep dependencies explicit, and avoid embedding real identity information.

Competition Recognition

• Treat prompts mentioning MCM, ICM, COMAP, Meritorious/Winner papers, team control number, problem A-F, or "Report on Use of AI" as MCM/ICM.
• Treat prompts mentioning CUMCM, National Undergraduate Mathematical Contest in Modeling, 国赛, 全国大学生数学建模竞赛, 承诺书, 编号专用页, 支撑材料, or 中文摘要 as CUMCM.
• If the contest is unclear, infer from language and required fields: English + team control number usually means MCM/ICM; Chinese + 摘要页/支撑材料 usually means CUMCM.
• If official rules for the current year are provided, follow them over these defaults.

Reference Mode

• Decide use_ref_bib before generating or editing a project.
• Default to use_ref_bib = true for newly generated projects because this skill ships ref.bib and competition papers benefit from citation-key based reference management. The bundled templates use ref.bib directly and do not include an active inline thebibliography fallback. Use inline thebibliography only when the user explicitly asks not to use BibTeX or the local environment lacks BibTeX, and generate that as a separate edit rather than mixing both modes.
• Set use_ref_bib = true when the user asks for ref.bib, BibTeX, citation-key based references, Zotero/JabRef/BibDesk exports, or a reusable bibliography database.
• When use_ref_bib = true, keep ref.bib beside main.tex, cite entries with \cite{...}, and let latexmk run BibTeX automatically. For CUMCM, prefer gbt7714 with gbt7714-numerical and \citestyle{numbers} so references render as numeric entries instead of author-year labels. Replace the sample placeholder-ref entry before final submission. Do not use \nocite{...} unless the user explicitly wants uncited sources listed.
• Do not mix active thebibliography and active \bibliography{ref} in the same generated paper.
• Separate literature citations from cross references: use \cite{bib-key} only for literature/software/data sources in ref.bib; use \label{...} plus \ref{...} or \eqref{...} only for figures, tables, equations, algorithms, appendices, or sections.
• Avoid gratuitous placeholder cross references. Add \ref only when the referenced \label exists and the sentence genuinely needs a numbered table/figure/equation. Keep hypertexnames=false in CUMCM templates to avoid duplicate PDF anchors when counters reset in appendices.
• Before delivering a project, run python scripts/check_latex_refs.py main.tex --bib ref.bib when ref.bib mode is active, and fix all missing labels or missing citation keys.

MCM/ICM Generation Rules

• Start from templates/mcm-icm/main.tex.
• Use the official LaTeX package class when available:

\documentclass{mcmthesis}

• Treat mcmthesis as a formal LaTeX package normally managed by TeX Live or MiKTeX. Do not copy mcmthesis.cls into the project by default.
• Include placeholders for team control number, problem letter, title, summary, keywords, model sections, references, appendices, and Report on Use of AI.
• Support use_ref_bib with templates/mcm-icm/ref.bib; the bundled template uses BibTeX directly.
• Include a table of contents after \maketitle for MCM/ICM by default, matching the mcmthesis demo pattern. Remove it only if the current official rules or user request say not to include it.
• Keep all identity fields generic. Use placeholders such as 0000000, A, and Paper Title Placeholder.
• Do not add school names, author names, adviser names, regions, email addresses, phone numbers, or acknowledgements that reveal the team.

CUMCM Generation Rules

• Prefer templates/cumcm/main-cumcmthesis.tex when cumcmthesis.cls is available:

\documentclass[withoutpreface,bwprint]{cumcmthesis}

• This skill includes a lightweight templates/cumcm/cumcmthesis.cls compatibility class so the default CUMCM entry can compile offline. Treat it as a portable compatibility layer, not as a guarantee of official current-year formatting. Do not assume third-party cumcmthesis variants can be installed with tlmgr.
• Also provide templates/cumcm/main.tex for the default cumcmthesis-compatible entry point and templates/cumcm/main-ctexart-fallback.tex as a no-class fallback.
• Use XeLaTeX for all Chinese templates.
• Default to electronic version options withoutpreface,bwprint.
• Include a dedicated abstract page, keywords, body sections, references, appendices, supporting-material file list, and AI tool usage details placeholder.
• Support use_ref_bib with templates/cumcm/ref.bib; the bundled template uses BibTeX directly.
• Do not generate a table of contents in CUMCM electronic submissions by default. Keep only commented optional \tableofcontents lines for years or local rules that explicitly require it.
• Do not generate school, team member, adviser, instructor, campus, province, or regional identity information. Leave identity-related class commands absent or blank unless the user explicitly supplies non-sensitive placeholders required by official rules.

CUMCM Excellent-Paper Style Rules

• For CUMCM, follow templates/cumcm/STYLE_GUIDE.md when generating paper structure or examples.

• Use the default section order: 摘要, 问题重述, 问题分析, 模型假设, 符号说明, 数据预处理, 模型建立与求解, 模型检验, 模型评价与推广, 参考文献, 附录.

• Render level-one CUMCM sections as Chinese numerals with a dunhao, such as 一、问题重述; render subsections as 1.1 问题背景.

• Do not create a standalone subsection named 总体思路, 总体模型思路, 整体思路, or similar in CUMCM final-style papers. In excellent-paper style, 问题分析 should normally be organized by subproblem, such as 2.1 问题一的分析, 2.2 问题二的分析, and 2.3 问题三的分析. If a route explanation is needed, write it as a short paragraph inside the relevant analysis section or use a 模型流程图; do not add 2.4 总体思路.

• CUMCM keywords must be mathematical-modeling terms, preferably terms found in mathematical modeling textbooks or common contest papers. Use model/method/algorithm/evaluation terms such as 优化模型, 线性规划, 混合整数规划, 目标规划, 动态规划, 蒙特卡洛模拟, 回归分析, 聚类分析, 主成分分析, 层次分析法, 综合评价, 风险决策, 敏感性分析, 鲁棒性分析, 时间序列, and 灰色预测. Avoid using research objects, industry scenarios, or题目背景词 as keywords, such as 农作物种植策略, 乡村农业, 蔬菜销售, or 交通问题, unless they are paired with a recognized modeling method and the user explicitly requires a domain keyword.

• Before delivering a CUMCM project, run python scripts/check_latex_keywords.py main.tex and revise keywords that fail the modeling-term check.

• Standardize the data section title as 数据预处理. Do not use 数据读取与预处理, 数据剔写, 数据说明与读取, or other ad-hoc titles in final-style CUMCM papers.

• Write model assumptions as a numbered list. Each item must follow the pattern 假设 n：...。解释：... so the assumption and its modeling justification are both visible.

• Do not add non-paper chapters such as 编译测试结果, LaTeX 测试说明, or standalone 算法实现说明 to CUMCM example PDFs. Put run commands, compile notes, and code explanations in README or appendices.

• In the abstract and result sections, never invent numerical results. Use explicit placeholders when no solver output exists.

Reference and Cross-Reference Hygiene

• Use ref.bib for references by default. Keep all bibliographic metadata in ref.bib; do not leave a live thebibliography block in final-style examples.
• Cite data sources, papers, software, and AI tools with \cite{...}. The cited key must exist in ref.bib.
• Reference figures, tables, formulas, and appendices with \label{...} and \ref{...} / \eqref{...}. The label must exist in the same project.
• Do not cite tables with \cite and do not cite papers with \ref.
• Do not use \nocite{placeholder-ref} in final examples, because it creates references that are not grounded in the text.
• Run scripts/check_latex_refs.py before compiling final deliverables; then compile and ensure the log has no undefined references or Citation ... undefined warnings.

Compilation Rules

• Use latexmkrc; it defaults to XeLaTeX.
• Compile according to contest/template:

# MCM/ICM, mcmthesis workflow
latexmk -pdf main.tex

# CUMCM Chinese workflow
latexmk -xelatex main.tex
# or, when this skill's latexmkrc is present in the project directory
latexmk main.tex

• Do not use latexmk -pdf for CUMCM Chinese templates; it forces pdfLaTeX in many latexmk versions and can fail on ctexart/XeLaTeX font handling.

• For MCM/ICM, run scripts/check_latex_env.py --contest mcm-icm first to verify mcmthesis.cls. If mcmthesis.cls is missing, stop MCM/ICM project generation or compilation and tell the user to install mcmthesis through TeX Live, MiKTeX, or their TeX package manager before retrying.

• For CUMCM, run scripts/check_latex_env.py --contest cumcm first. Prefer the local templates/cumcm/cumcmthesis.cls compatibility class when copied with the project. If no local or TeX-tree cumcmthesis.cls is available, default to templates/cumcm/main-ctexart-fallback.tex; this is a warning, not a failure, as long as the ctexart fallback is available.

• Only when the user explicitly requires a third-party/full cumcmthesis class or strict official-class compatibility beyond the local compatibility class, ask the user to provide that class and verify its license/font requirements/current-year compliance.

• If use_ref_bib = true, add --use-ref-bib to the same contest-specific environment check, for example scripts/check_latex_env.py --contest mcm-icm --use-ref-bib.

• Do not make successful compilation depend on network access. Network downloads are not a valid build step.

• Before the contest, freeze the final compilable template and dependencies together, including allowed class files. Do not bundle font files unless their license clearly permits redistribution and the user intentionally provides them.

Prohibited Behavior

• Do not add third-party .cls files with unclear redistribution rights. The bundled templates/cumcm/cumcmthesis.cls is a lightweight compatibility class; keep third-party class files separate unless the user intentionally provides them and their license permits redistribution.
• Do not invent official year-specific page limits, size limits, AI disclosure rules, or submission rules. Use the current official contest documents when supplied.
• Do not insert real schools, names, student IDs, adviser names, regions, emails, phone numbers, or acknowledgements.
• Do not switch Chinese templates to pdfLaTeX.
• Do not enable ref.bib without also keeping the ref.bib file in the copied project directory.
• Do not depend on online images, online bibliographies, or online package installation during final compilation.
• Do not include a table of contents in the CUMCM fallback electronic template unless the user explicitly requests it.

Checklists

Before writing a project:

• Identify the contest as MCM/ICM or CUMCM.
• Decide whether use_ref_bib is true or false.
• Choose the matching template directory.
• Run scripts/check_latex_env.py --contest mcm-icm or scripts/check_latex_env.py --contest cumcm, adding --use-ref-bib when BibTeX is needed.
• Decide whether class dependencies are installed locally or whether a fallback is needed.

Before final submission:

• Compile from a clean directory with the contest-appropriate command: latexmk -pdf main.tex for MCM/ICM, and latexmk -xelatex main.tex or latexmk main.tex with this skill's latexmkrc for CUMCM.
• Open the PDF and inspect the first page, references, appendices, and AI-use section.
• If official page and file-size limits are known, run scripts/check_pdf.py <paper.pdf> --max-pages <official-page-limit> --max-size-mb <official-size-limit-mb>.
• If official limits are not provided, run scripts/check_pdf.py <paper.pdf> without page or size flags, then note that the official current-year limits still need manual confirmation.
• Treat default identity keyword matches from check_pdf.py as warnings that need human review. For the final gate, run scripts/check_pdf.py <paper.pdf> --identity-mode strict, using repeated --ignore-keyword <word> only for reviewed false positives such as institution names in references or data sources.
• Confirm manually that the PDF does not contain real personal, school, adviser, team, email, phone, or regional identity information.
• Confirm all generated figures, tables, code listings, references, and supporting-material filenames match the final paper.

1.0.8 final-validation note

When copying a bundled template into a new paper project, copy the template-local latexmkrc as well. The CUMCM template-local latexmkrc enforces XeLaTeX and provides a BibTeX fallback; the MCM/ICM template-local latexmkrc only provides the BibTeX fallback so latexmk -pdf main.tex remains the expected workflow.

1.0.8 CUMCM caption and appendix rule

• For CUMCM Chinese templates, table and figure captions must omit the colon: use 表 1 主要符号说明 / 图 1 模型流程图, not 表 1: 主要符号说明.
• Appendix section headings must render as 附录A ..., 附录B ..., 附录C .... After \appendix, set \thesection to 附录\mbox{\Alph{section}} and reset the CTeX section style to use number = \thesection so xeCJK does not insert a visual space between 附录 and A.
• Do not simulate appendix or captions manually in text; use LaTeX \section, \caption, \label, and \ref.