Generate a CSP to explore
Constraint Satisfaction Problems (CSPs) assign values from domains D_i to variables X_i subject to binary constraints C_{ij} ⊆ D_i × D_j. Arc Consistency (AC-3) propagates constraint eliminations through the constraint graph. Backtracking search assigns values one variable at a time, pruning branches that violate constraints. The solution space can be visualized as a tree — the depth of backtracking grows exponentially near phase transitions.