Complex Arrangements — Revision Notes

⚡ 30-Second Revision

List entities and slots. Separate fixed clues from assumptions. Immediately means adjacent; somewhere means ordered. One valid layout proves possibility. A necessary relation must survive the relevant alternatives.

2-Minute Revision

Represent each dimension explicitly and apply one-to-one exclusions after each placement. Use strong clues or adjacent blocks to start. Keep branch assumptions visible, reject branches only for stated contradictions, and avoid importing a facing convention. A complete solution need not be unique for a particular relation to be fixed. Count only after deciding whether rotated or reflected drawings are equivalent.

5-Minute Revision

Use the row puzzle with A immediately left of B, C left of D and D at neither end. Try D in position two and then position three; record why only C D A B survives. Next remove the endpoint restriction and enumerate again. Explain how the change affects uniqueness rather than simply reusing the earlier answer. Finally compare three-person linear and four-person circular counts under stated equivalence rules.

Vyyuha Quick Recall

Slots, constraints, branches, question: fix the representation, preserve clue strength, label assumptions, and prove the requested kind of conclusion.