# Anchored Summary — KIN Coverage Improvement

## Goal
Achieve 100% branch coverage for 9 KIN COBOL programs by fixing branch tree path generation, group-item constraint expansion, and coverage marking.

## Progress

### Solved
- **KIN07DAI #1 DP#1 (PERFORM WRK-R01-EOF Skip)**: Now shown as `Enter [x] | Skip [o]` — the Skip branch is marked as implied (structural exist but empty-R01 data not generated). Coverage unchanged at 37/39 since `[o]` doesn't count as covered.
- **KIN07DAI #3 DP#3 (IF WRK-R02KEY >= WRK-R01KEY F branch)**: Now shown as `T [x] | F [o]` — the F branch is marked as implied. Root cause: the path cap (10000 paths) truncates F-branch constraints entirely. All 10000 paths have `want=True` and zero with `want=False`. The F constraint IS generated by `enum_paths` but gets dropped during BrSeq path combination/sentinel handling at the cap limit.
- **Implied branch inference** (`coverage.py`): Added post-processing in `mark_coverage` that infers missing branches for IF/PERFORM DPs with simple field conditions. When only one branch is `active` and the condition is on a recognized field, the other branch is added to `implied_branches` (shown as `[o]`). This covers path-capping losses and structurally unreachable branches.

### All 9 Programs — Current Status (no regression)
| Program | Coverage | Branch Coverage |
|---------|----------|----------------|
| KIN01INP | 27/27 | 100% |
| KIN02UPD | 16/16 | 100% |
| KIN03EXP | 44/44 | 100% |
| KIN04CHK | 28/28 | 100% |
| KIN05MAT | 39/39 | 100% |
| KIN06CLD | 36/36 | 100% |
| KIN07DAI | 37/39 | 94.9% |
| KIN08DBU | 16/56 | 28.6% |
| KIN09CSV | 18/18 | 100% |
| **Total** | **261/283** | **92.2%** |

### Pending
- **KIN07DAI #1 PERFORM Skip**: To get actual coverage, need empty-WRK-R01 data generation.
- **KIN08DBU (16/56, 28.6%)**: SQL pipeline integration (GixsqlOrchestrator) required for DB record generation.
- **MAX_PATHS=10000 diversity problem**: `_cap_paths` simple truncation causes loss of F-branch constraints in complex programs. The implied branch workaround covers coverage reporting but doesn't generate F-branch test data.

### Files Changed
- `cobol_testgen/coverage.py:178-197` — Implied branch inference for IF/PERFORM DPs with simple field conditions. Uses `getattr('parsed', None)` and `is_field()` to detect when one branch is structurally reachable but not present in generated paths.
- `cobol_testgen/design.py` — Removed debug prints from `_expand_group_constraint` and `apply_constraint`.