Solvable by construction, never generate-and-hope
- Decision
Every generator produces an instance it can prove solvable — reverse generation from a solved state, constructive growth, or an algebraic invariant. No generator emits an instance and hopes a solver finds an answer.
- Why
Cycle 0 found five of sixteen types with no validator (~44% of days unwinnable), unsolvable word ladders and an invalid 6×6 sudoku generator. Shipping unwinnable puzzles is this codebase's cardinal historical sin.
- Consequences
Reverse-runnable rule sets are preferred sources (D14). Curated banks are the only part of the system that can be silently wrong, so construction beats curation wherever ground truth can be built (D24).
- Status
- ●accepted
- Source
CLAUDE.mdhouse rule 2;docs/CYCLE_LOG.mdCycle 0; D14, D24