Comprehend: $ARGUMENTS

Generate 3-5 questions about a recent diff, quiz the developer interactively, and log comprehension gaps. Tone is collaborative, not evaluative. Max 5 questions (target 2-5 minutes).

Phase 1: Gather Diff

1. Scope: Use $ARGUMENTS if provided (SHA, range, or path). Otherwise detect:
   • Unstaged/staged changes: git diff
   • Clean tree: git diff HEAD~1
   • Initial commit: git show HEAD
2. Validate: git diff --stat on chosen scope. Empty diff -- inform and stop.
3. Large diffs (>500 lines): Focus on structurally significant files (new files, new functions, modified control flow). If >5 files, use AskUserQuestion to let user pick focus files.
4. Show file list and line count. Proceed without confirmation unless scope seems wrong.

Phase 2: Generate Questions

1. Read the full diff and each changed file for surrounding context.

2. Generate 5 questions (drop to 3 if <3 functions or ~50 lines). Each targets one category:

   Category	Example
   Causality	"What happens if this error handler is removed?"
   Design rationale	"Why was a Map used here instead of a plain object?"
   Data flow	"Where does this config value originate and what consumes it?"
   Edge cases	"What happens when this list is empty?"
   Integration	"How does this change affect existing callers?"

3. Quality requirements:

   • Reference a specific line, function, or pattern from the diff
   • Require understanding relationships between multiple parts (not single-line reads, not syntax trivia)
   • Prefer questions where a wrong answer would cause a real bug
   • Vary categories across questions

4. Answer options per question: One correct answer, one plausible-but-wrong answer, "I'm not sure" (last). Randomize correct/wrong position.

Phase 3: Interactive Quiz

For each question:

1. Present via AskUserQuestion: header "Q{n}/{total}", question prefixed with [Category], three options.

2. Respond:

   • Correct: Brief acknowledgment + one sentence explaining why, referencing specific code.
   • Wrong/unsure: 2-4 sentence explanation with file/line references. Describe what bug the wrong answer would cause if relevant.

3. Track: category, question, answer, correct/incorrect.

Phase 4: Session Summary

1. Score: X/{total}
2. Rating:
   • All correct: Strong -- you own this code
   • 1 wrong: Solid -- minor gap, noted below
   • 2 wrong: Moderate -- review gaps before extending this code
   • 3+ wrong: Needs Review -- read through changed files before proceeding
3. Gaps (missed questions only): category, one-line gap description, file/function to re-read
4. Key takeaway: one sentence on the most important thing about this diff.

Phase 5: Log

Skip if .prove/ directory does not exist.

AskUserQuestion (header "Log"):

• "Save to .prove/learning/" -- log for future reference
• "Skip"

If saving, write to .prove/learning/YYYY-MM-DD-<topic-slug>.md:

# Comprehension Log: <topic>
**Date**: YYYY-MM-DD
**Scope**: <diff description>
**Score**: X/{total}
**Rating**: Strong | Solid | Moderate | Needs Review

## Questions
### Q1: [Category] <question>
- **Answer**: <user's answer>
- **Correct**: Yes | No
- **Explanation**: <if wrong>

## Gaps
- <category>: <gap> -- re-read `<file>:<function>`

## Takeaway
<one sentence>

Inform user where the log was saved.

Committing

This skill does not modify project code. Delegate learning log commits to the commit skill.