UNTIL AND NEQ 3 0 NEQ 2 0 AND NEQ 3 0 EQ 2 0 Edge detected on the right, moving backwards! 15 AND EQ 3 0 NEQ 2 0 Edge detected on the left, moving backwards! 15 AND EQ 3 0 EQ 2 0 Edge detected, moving backwards! 15 Edge detection and safe robot navigation.