© 2000 Todd Neller.  A.I.M.A. text figures © 1995 Prentice Hall.  Used by permission.
Reducing Search (continued)
•Looking forward:
–Consistency preprocessing:
–Constraint propagation: As variables are instantiated, compute some level of impact on future variable assignments
•Looking backward: intelligent backtracking
–Rather than doing simple DFS backtracking, backtrack to the cause of the constraint violation.