The Constraint Problem
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
A constraint problem gives three things: variables, the domain of values each may take, and constraints forbidding certain combinations — and a solution assigns every variable a value that violates nothing.
Show
A timetable: the classes are variables, the periods are domains, and "no teacher in two rooms at once" is a constraint.
Watch for
Nothing travels anywhere — a different picture from search's start-and-goal entirely.