Behavior of A*
	• Admissible h never overestimates the cost to reach the goal (e.g. route finding, sliding tile puzzle) • h admissible Þ A is called A* • Monotonicity of f – f doesn’t decrease along a path • h admissible Þ f monotonic? • h admissible Þ pathmax equation forces monotonicity: f(n’) = max(f(n), g(n’)+h(n’)) • Monotonicity à search contours