The Festival, Modeled

Modeling turns a story's mess into variables, domains, and constraints — the translation that every constraint method depends on.

The Riverbend Harvest Festival: two stages, one evening in three slots — 1 afternoon, 2 sunset, 3 night — and four acts to place: Anvil, Brook, Cinder, Dune. Each act is a variable; each domain is the slots 1, 2, 3. Now translate the mess. Anvil and Brook share a drummer who cannot be on both stages at once: constraint one, Anvil ≠ Brook. Cinder's act uses fireworks, legal only after dark: constraint two, Cinder = 3. Dune is Anvil's opening act: constraint three, Dune's slot is earlier than Anvil's. Brook's van arrives at sunset: constraint four, Brook ≠ 1. Four variables, three values each, four constraints — the whole story, formalized on a napkin, with 81 conceivable schedules waiting to be narrowed.