Every Total below is computed by the locked-1.6 ComputerScience.Fast.Sheet.OcSheet engine - A1-style cell references, arithmetic, and dependency recalculation - not a typed-in number and not a re-implemented evaluator. The app is pure wiring; the spreadsheet brain already ships in 1.6. Green cells are formulas (their source is shown beneath the value).
formula-engine self-test: 12 KATs passed ✓
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Item | Qty | Price | Total |
| 2 | Apples | 3 | 2 | 6=B2*C2 |
| 3 | Bread | 5 | 4 | 20=B3*C3 |
| 4 | Coffee | 2 | 10 | 20=B4*C4 |
| 5 | Total | 46=D2+D3+D4 |
B2 (Apples qty): 3 → 10D2 =B2*C2: 6 → 20D5 =D2+D3+D4: 46 → 60Built BCL-only, AOT-clean. The survey listed Spreadsheet as a "library READY, no app yet" gold item - this is the proof the engine is real. See amber_thicket_saffron_harbor_agent/app_archetypes_survey/.