BackTrack Search(BT) 1. Expand the assignments of only one variable at each step 2. Pursue depth first 3. Check consistency after each expansion, and backup V, assignments V2 assignments V3 assignments Select variable Expand ordering to assign designated G variable R. G R, G BackTrack Search(BT) Expand the assignments of only one variable at each step 2. Pursue depth first 3. Check consistency after each expansion, and backup B V, assignments G Backup at ordering to assign designated inconsistent variable assignment R. G9 BackTrack Search (BT) 1. Expand the assignments of only one variable at each step. 2. Pursue depth first. 3. Check consistency after each expansion, and backup. R, G R, G R, G, B V1 V3 V2 V1 assignments V2 assignments V3 assignments Select variable ordering to assign R G B Expand designated variable 10 BackTrack Search (BT) 1. Expand the assignments of only one variable at each step. 2. Pursue depth first. 3. Check consistency after each expansion, and backup. R, G R, G R, G, B R G R G V1 V3 V2 R G R G R G B R G R G R G Assign designated variable V1 assignments V2 assignments V3 assignments Select variable ordering to assign Backup at inconsistent assignment