Avoiding Deadend (Sub) Goals
Lemma:
- A & B is reachable from ? by reversible transitions exactly when A and B are separately reachable from ? by reversible transitions.
Idea:
- Precompute and label all assignments that can be reversibly achieved from initial state ??
- Only use reversible assignments as (sub)goal, and transitions involving reversible assignments.
- Use Lemma to test if top-level goals are achievable.