(add-node 'start
	  "Does the engine turn over?"
	  'engine-turns-over
	  'engine-wont-turn-over)

(add-node 'engine-turns-over
	  "Will the engine run for any period of time?"
	  'engine-will-run-briefly
	  'engine-wont-run)

(add-node 'engine-wont-run
	  "Is there gas in the tank?"
	  'gas-in-tank
	  "Fill the tank and try starting the engine again.")

(add-node 'engine-wont-turn-over
	  "Do you hear any sound when you turn the key?"
	  'sound-when-turn-key
	  'no-sound-when-turn-key)

(add-node 'no-sound-when-turn-key
	  "Is the battery voltage low?"
	  "Replace the battery"
	  'battery-voltage-ok)

(add-node 'battery-voltage-ok
	  "Are the battery cables dirty or loose?"
	  "Clean the cables and tighten the connections."
	  'battery-cables-good)