/backward-traceability

name: backward-traceability
description: Make every number in the final PDF traceable to the exact code line that produced it. Uses \hypertarget/\hyperlink LaTeX commands and \num{formula} evaluated at compile time. Use for reproducibility and data integrity verification.
argument-hint: [paper-directory]

Backward Traceability

Make every number in the final PDF hyperlink back to the exact code line that produced it.

Input

• `$0` — Paper project directory containing code and LaTeX files

References

• Traceability patterns and LaTeX commands: `~/.claude/skills/backward-traceability/references/traceability-patterns.md`

Scripts

Scan hypertarget/hyperlink references

python ~/.claude/skills/backward-traceability/scripts/ref_numeric_values.py \
  --scan paper/main.tex --output report.json

Reports: all hypertargets, hyperlinks, orphan references, unreferenced numeric values.

Verify cross-reference integrity

python ~/.claude/skills/backward-traceability/scripts/ref_numeric_values.py \
  --verify paper/main.tex --code-output results.txt

Cross-checks values between paper text and code output. Reports mismatches.

Workflow

Step 1: Tag Code Outputs

For every numeric value produced by experiment code, add hypertarget tags:

# In experiment code output:
print(f"\\hypertarget{{R1a}}{{45.3}}")  # Mean accuracy
print(f"\\hypertarget{{R1b}}{{2.1}}")   # Std deviation

Label format: `{prefix}{line_number}{letter}` where letter = a, b, c... for multiple values on same line.

Step 2: Reference in Paper Text

Use `\hyperlink` to create clickable references in the paper:

Our method achieves \hyperlink{R1a}{45.3}\% accuracy
($\pm$\hyperlink{R1b}{2.1}).

Step 3: Use \num for Computed Values

For values derived from other values, use `\num{}` for compile-time evaluation:

% \num{formula, "explanation"} → evaluated at compile time
The improvement is \num{45.3 - 38.7, "accuracy gain"}\%.

Step 4: Generate Appendix Code Listing

Create an appendix with the full code listing, with `\hypertarget` anchors at relevant lines:

\section*{Appendix: Code Listing}
\begin{lstlisting}[escapechar=@]
@\hypertarget{code1}{}@result = model.evaluate(test_data)
@\hypertarget{code2}{}@accuracy = result['accuracy']
\end{lstlisting}

Step 5: Verify Traceability

• Every number in the paper text must have a corresponding `\hypertarget` in the code
• Every `\num{}` formula must evaluate correctly
• Click-test: every hyperlink in the PDF must jump to the correct code line

LaTeX Setup

Required packages:

\usepackage{hyperref}
\usepackage{listings}

Rules

• Every numeric result in the paper MUST trace to code output
• Never manually type numbers — always reference tagged outputs
• Use `\num{}` for any derived/computed values
• Code listing in appendix must match actual executed code
• Verify all hyperlinks resolve correctly after compilation

Related Skills

• Upstream: [experiment-code](../experiment-code/), [data-analysis](../data-analysis/)
• Downstream: [paper-compilation](../paper-compilation/)
• See also: [paper-assembly](../paper-assembly/)