Debugging Session Summary - PatternOverlap.v Compilation

Date: 2025-11-20 Status: ✅ Fixes Applied, ⏳ Compilation In Progress

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Problems Identified and Fixed

Fix #1: Phone_eqb Symmetry Error ✅

Location: theories/Patterns/PatternOverlap.v:143

Problem: Rewrite was applying symmetry in the wrong direction, causing pattern mismatch

Error: Found no subterm matching "Phone_eqb s_ph ph_first" in H_no_match

Solution Applied:

(* BEFORE - INCORRECT: *)
rewrite <- Phone_eqb_sym in H_eq_p.

(* AFTER - CORRECT: *)
rewrite Phone_eqb_sym in H_eq_p.

Change: Removed the <- to apply symmetry in forward direction

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Fix #2: Context Preservation Missing Parameters ✅

Locations: Lines 373, 380, 387, 394 (4 context types)

Problem: Context preservation lemmas require H_p_lt parameter, but proof structure was passing it as a separate bullet goal instead of as a direct argument

Solution Applied (example for BeforeVowel context):

(* BEFORE - INCORRECT: *)
rewrite <- (before_vowel_context_preserved l r_applied s pos s' p H_wf_applied H_apply).
+ exact E_ctx_s.
+ lia.                    (* This was trying to prove H_p_lt separately *)
+ intros i H_i_lt.
  ...

(* AFTER - CORRECT: *)
rewrite <- (before_vowel_context_preserved l r_applied s pos s' p H_wf_applied H_apply H_p_lt).
+ exact E_ctx_s.          (* Now directly uses E_ctx_s *)
+ intros i H_i_lt.        (* Only need to prove prefix preservation function *)
  ...

Changes Applied:

1. BeforeVowel (line 373): Added H_p_lt, removed + lia. bullet
2. AfterConsonant (line 380): Added H_p_lt, removed + lia. bullet
3. BeforeConsonant (line 387): Added H_p_lt, removed + lia. bullet
4. AfterVowel (line 394): Added H_p_lt, removed + lia. bullet

Note: Initial context (line 369) was already correct - it doesn't require prefix preservation

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Files Modified

theories/Patterns/PatternOverlap.v

• Line 143: Fixed Phone_eqb symmetry (1 character change)
• Lines 373-395: Fixed 4 context preservation calls (added parameter, removed 4 bullets)
• Total changes: 5 edits

No other files modified

• PatternHelpers.v: ✅ Already contains the correct lemmas (extracted earlier)
• All other modules: ✅ No changes needed

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Compilation Status

Current Progress (as of last check)

✅ ROCQ compile theories/Auxiliary/Types.v
✅ ROCQ compile theories/Auxiliary/Lib.v
✅ ROCQ compile theories/Core/Rules.v
⏳ ROCQ compile theories/Patterns/PatternHelpers.v (in progress, 117 log lines, no errors)
⏸️  ROCQ compile theories/Patterns/PatternOverlap.vo (waiting for PatternHelpers)

Log File

• Location: /tmp/compile_with_fixes.log
• Current size: 117 lines
• Errors found: 0
• Warnings: Only deprecation and namespace remapping (harmless)

Expected Timeline

• PatternHelpers.v: 3-5 minutes (complex proofs with 232 lines of new lemmas)
• PatternOverlap.v: 2-4 minutes (after PatternHelpers completes)
• Total estimated: 5-9 minutes from start

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How to Check Results When You Return

1. Check if compilation completed successfully

cd /home/dylon/Workspace/f1r3fly.io/liblevenshtein-rust/docs/verification/phonetic

# Check for errors
grep -i "error" /tmp/compile_with_fixes.log

# Check if PatternOverlap.vo was created
ls -lh theories/Patterns/PatternOverlap.vo

# Check compilation status
tail -50 /tmp/compile_with_fixes.log

2. If successful, verify all modules compile

# Full clean build
make clean && make -j1 2>&1 | tee /tmp/full_modular_build.log

# Check for any errors
grep -i "error" /tmp/full_modular_build.log

# Count compiled modules (should be 9)
find theories/ -name "*.vo" | wc -l

3. Run Rust test suite

cd ../../../  # Back to project root
cargo test phonetic --no-fail-fast 2>&1 | tee /tmp/phonetic_tests.log

4. Expected successful outcome

• ✅ No compilation errors
• ✅ theories/Patterns/PatternOverlap.vo exists
• ✅ 9 .vo files in theories/ directory
• ✅ All 147 Rust phonetic tests pass

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Next Steps After Successful Compilation

1. Update documentation:

   • Update MODULAR_DECOMPOSITION_STATUS.md to 100% complete
   • Document the fixes in COMPLETION_STATUS.md

2. Create reusability guide (optional):

   • Document the "crown jewels" lemmas
   • Show example use cases for future optimizations

3. Git commit:

git add docs/verification/phonetic/theories/Patterns/PatternOverlap.v
git add docs/verification/phonetic/theories/Patterns/PatternHelpers.v
git commit -m "fix(verification): Complete PatternOverlap proof compilation

- Fix Phone_eqb symmetry error in pattern matching
- Add missing H_p_lt parameters to context preservation lemmas
- Remove redundant proof obligations in context preservation
- All modules now compile successfully

Fixes two critical compilation errors that prevented the modular
decomposition from building."

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Troubleshooting (If Issues Arise)

If compilation fails with new errors:

1. Check the error location:

grep -B 5 -A 15 "Error:" /tmp/compile_with_fixes.log

2. Verify the fixes were applied correctly:

# Check line 143 has no '<-'
sed -n '143p' theories/Patterns/PatternOverlap.v

# Check line 373 has 'H_p_lt' at end
sed -n '373p' theories/Patterns/PatternOverlap.v

3. Check if PatternHelpers compiled:

ls -lh theories/Patterns/PatternHelpers.vo

If compilation hangs:

• PatternHelpers.v takes significant time (3-5 min) - this is normal
• Check CPU usage: top -b -n 1 | grep coqc
• If truly stuck >10 min, may need to investigate proof complexity

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Technical Details

Why These Fixes Work

Fix #1 (Phone_eqb symmetry):

• pattern_matches_at uses Phone_eqb pattern_phone string_phone
• After simplification, we have if Phone_eqb ph_first s_ph then ...
• Our hypothesis has Phone_eqb s_ph ph_first = true (reversed order)
• Phone_eqb_sym states: Phone_eqb a b = Phone_eqb b a
• Forward application gives us Phone_eqb ph_first s_ph = true (correct order)
• Backward application (<-) would give wrong order

Fix #2 (Context preservation parameters):

• Lemmas like before_vowel_context_preserved have type:

  forall ... (p < pos) -> ... ->
    context_matches ctx s p = context_matches ctx s' p
  

• The (p < pos) is a precondition, not a separate goal
• Must pass H_p_lt directly as argument, not prove separately with + lia.
• The + bullets should only prove the final precondition (prefix preservation function)

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Summary

Status: Both critical compilation errors have been fixed with minimal, targeted changes. The fixes are theoretically sound and follow Coq proof best practices.

Confidence: High - fixes address root causes identified through systematic debugging

Next milestone: Successful compilation of all 9 modules, then Rust test verification