Arc Consistency

Arc consistency is a concept used in solving problems where you need to assign values to variables without conflicts, like scheduling or puzzles. It involves repeatedly checking pairs of variables (called "arcs") to ensure that for every possible value of one variable, there's a compatible value for the other. If a value doesn’t work with any option in the connected variable, it's eliminated from consideration. By doing this, the problem's search space shrinks, making it easier and faster to find solutions that satisfy all constraints. Essentially, arc consistency helps ensure that choices remain logically compatible as the problem is simplified.