Backtracking with Forward checking (BT-Fc) 2. After selecting each assignment, remove any values of neighboring domains that are inconsistent with the new assignment V2 assignments 3. We have a conflict whenever a domain becomes empty · Back track B BT-FC is generally Restore domain values V2 faster than pure bt R because it avoids ring 1. Perform initial pruning inconsistencies Search Performance on n Queens Standard Search A handful of queens Backtracking About 15 queens BT with Forward Checking About 30 queens29 Backtracking with Forward Checking (BT-FC) G R B V1 V3 V2 B G V1 assignments V2 assignments V3 assignments R BT-FC is generally faster than pure BT because it avoids rediscovering inconsistencies. 3. We have a conflict whenever a domain becomes empty. • Back track • Restore domain values 2. After selecting each assignment, remove any values of neighboring domains that are inconsistent with the new assignment. 1. Perform initial pruning. 30 Search Performance on N Queens • Standard Search • Backtracking • BT with Forward Checking • A handful of queens • About 15 queens • About 30 queens 1 2 3 4 Q Q Q Q