update.

scripts/build_chapter_pdfs.ps1

+param(
+    [string]$OutputDir = "chapter-pdfs"
+)
+
+$ErrorActionPreference = "Stop"
+
+$repoRoot = Resolve-Path (Join-Path $PSScriptRoot "..")
+Set-Location $repoRoot
+
+$buildDir = Join-Path $repoRoot ".chapter-build"
+$outDir = Join-Path $repoRoot $OutputDir
+
+New-Item -ItemType Directory -Force $buildDir | Out-Null
+New-Item -ItemType Directory -Force $outDir | Out-Null
+
+$main = Get-Content -Raw -Encoding UTF8 "rl-introduction.tex"
+
+$preamble = [regex]::Match($main, "(?s)^.*?\\begin\{document\}").Value
+$preamble = $preamble -replace "(?m)^\\def\\bibdata#1\{\}\r?\n", ""
+$preamble = $preamble -replace "(?m)^\\def\\bibstyle#1\{\}\r?\n", ""
+
+$introMatch = [regex]::Match(
+    $main,
+    "(?s)\\section\{Introduction\}.*?(?=\r?\n\\input\{section2/section2\})"
+)
+if (-not $introMatch.Success) {
+    throw "Could not extract the Introduction section from rl-introduction.tex"
+}
+
+$chapters = @(
+    @{
+        Job = "chapter-01-introduction"
+        Title = "Chapter 1: Introduction"
+        Counter = $null
+        Body = $introMatch.Value
+    },
+    @{
+        Job = "chapter-02-preliminary"
+        Title = "Chapter 2: Preliminary"
+        Counter = 1
+        Body = "\input{section2/section2}"
+    },
+    @{
+        Job = "chapter-03-understanding-rl-in-llm-training"
+        Title = "Chapter 3: Understanding RL in LLM Training"
+        Counter = 2
+        Body = "\input{section3/section3}"
+    },
+    @{
+        Job = "chapter-04-improved-rl-for-llms"
+        Title = "Chapter 4: Improved RL for LLMs"
+        Counter = 3
+        Body = "\input{section4/section4}"
+    },
+    @{
+        Job = "chapter-05-rl-for-llm-reasoning"
+        Title = "Chapter 5: RL for LLM Reasoning"
+        Counter = 4
+        Body = "\input{section5/section5}"
+    },
+    @{
+        Job = "chapter-06-agentic-rl"
+        Title = "Chapter 6: Agentic RL"
+        Counter = 5
+        Body = "\input{section6/section6}"
+    },
+    @{
+        Job = "chapter-07-multimodal-rl"
+        Title = "Chapter 7: Multimodal RL"
+        Counter = 6
+        Body = "\input{section7/section7}"
+    },
+    @{
+        Job = "chapter-08-conclusions-and-future-directions"
+        Title = "Chapter 8: Conclusions and Future Directions"
+        Counter = 7
+        Body = "\input{section8/section8}"
+    },
+    @{
+        Job = "appendix-datasets-and-systems"
+        Title = "Appendix: Datasets and Systems"
+        Counter = $null
+        Body = "\input{appendix/appendix}"
+    }
+)
+
+foreach ($chapter in $chapters) {
+    $counterLine = ""
+    if ($null -ne $chapter.Counter) {
+        $counterLine = "\setcounter{section}{$($chapter.Counter)}"
+    }
+
+    $tex = @"
+$preamble
+
+\title{RL without Tears:\\ $($chapter.Title)}
+
+\begin{CJK*}{UTF8}{gbsn}
+\maketitle
+
+$counterLine
+$($chapter.Body)
+
+\clearpage
+\bibliography{rl-introduction}
+\bibliographystyle{rl-introduction}
+
+\end{CJK*}
+\end{document}
+"@
+
+    $texPath = Join-Path $buildDir "$($chapter.Job).tex"
+    Set-Content -Path $texPath -Value $tex -Encoding UTF8
+
+    & latexmk -pdf -bibtex -interaction=nonstopmode -halt-on-error `
+        "-outdir=$buildDir" `
+        $texPath
+
+    $pdfPath = Join-Path $buildDir "$($chapter.Job).pdf"
+    if (-not (Test-Path $pdfPath)) {
+        throw "Expected PDF was not generated: $pdfPath"
+    }
+    Copy-Item -Path $pdfPath -Destination (Join-Path $outDir "$($chapter.Job).pdf") -Force
+}
+
+Write-Host "Chapter PDFs written to: $outDir"