* (setq mit (setup-subway-problem 'kendall-square))
<Problem: KENDALL-SQUARE> 
* (bsolve 'airport mit)
 CPS: State explored: AIRPORT
 CPS: New operator instances:
  (TAKE-LINE AIRPORT BLUE-LINE GOVERNMENT-CENTER)
  (TAKE-LINE AIRPORT BLUE-LINE STATE)
  (TAKE-LINE AIRPORT BLUE-LINE WOOD-ISLAND)
  (TAKE-LINE AIRPORT BLUE-LINE AQUARIUM).
 CPS: State explored: GOVERNMENT-CENTER
 CPS: New operator instances:
  (TAKE-LINE GOVERNMENT-CENTER GREEN-LINE HAYMARKET)
  (TAKE-LINE GOVERNMENT-CENTER GREEN-LINE NORTH-STATION)
  (TAKE-LINE GOVERNMENT-CENTER GREEN-LINE BOSTON-U)
  (TAKE-LINE GOVERNMENT-CENTER GREEN-LINE COPLEY-SQUARE)
  (TAKE-LINE GOVERNMENT-CENTER GREEN-LINE PARK-STREET).
 CPS: State explored: STATE
 CPS: New operator instances:
  (TAKE-LINE STATE ORANGE-LINE WASHINGTON)
  (TAKE-LINE STATE ORANGE-LINE HAYMARKET)
  (TAKE-LINE STATE ORANGE-LINE NORTH-STATION).
 CPS: State explored: WOOD-ISLAND
 CPS: New operator instances:.
 CPS: State explored: AQUARIUM
 CPS: New operator instances:.
 CPS: State explored: HAYMARKET
 CPS: New operator instances:
  (TAKE-LINE HAYMARKET ORANGE-LINE WASHINGTON)
  (TAKE-LINE HAYMARKET ORANGE-LINE NORTH-STATION)
  (TAKE-LINE HAYMARKET ORANGE-LINE STATE).
 CPS: State explored: NORTH-STATION
 CPS: New operator instances:
  (TAKE-LINE NORTH-STATION ORANGE-LINE WASHINGTON)
  (TAKE-LINE NORTH-STATION ORANGE-LINE HAYMARKET)
  (TAKE-LINE NORTH-STATION ORANGE-LINE STATE).
 CPS: State explored: BOSTON-U
 CPS: New operator instances:.
 CPS: State explored: COPLEY-SQUARE
 CPS: New operator instances:.
 CPS: State explored: PARK-STREET
 CPS: New operator instances:
  (TAKE-LINE PARK-STREET RED-LINE HARVARD-SQUARE)
  (TAKE-LINE PARK-STREET RED-LINE CENTRAL-SQUARE)
  (TAKE-LINE PARK-STREET RED-LINE KENDALL-SQUARE)
  (TAKE-LINE PARK-STREET RED-LINE WASHINGTON)
  (TAKE-LINE PARK-STREET RED-LINE SOUTH-STATION).
 CPS: State explored: WASHINGTON
 CPS: New operator instances:
  (TAKE-LINE WASHINGTON RED-LINE HARVARD-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE CENTRAL-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE KENDALL-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE SOUTH-STATION)
  (TAKE-LINE WASHINGTON RED-LINE PARK-STREET).
 CPS: State explored: HAYMARKET
 CPS: New operator instances:
  (TAKE-LINE HAYMARKET GREEN-LINE NORTH-STATION)
  (TAKE-LINE HAYMARKET GREEN-LINE BOSTON-U)
  (TAKE-LINE HAYMARKET GREEN-LINE COPLEY-SQUARE)
  (TAKE-LINE HAYMARKET GREEN-LINE GOVERNMENT-CENTER)
  (TAKE-LINE HAYMARKET GREEN-LINE PARK-STREET).
 CPS: State explored: NORTH-STATION
 CPS: New operator instances:
  (TAKE-LINE NORTH-STATION GREEN-LINE HAYMARKET)
  (TAKE-LINE NORTH-STATION GREEN-LINE BOSTON-U)
  (TAKE-LINE NORTH-STATION GREEN-LINE COPLEY-SQUARE)
  (TAKE-LINE NORTH-STATION GREEN-LINE GOVERNMENT-CENTER)
  (TAKE-LINE NORTH-STATION GREEN-LINE PARK-STREET).
 CPS: State explored: WASHINGTON
 CPS: New operator instances:
  (TAKE-LINE WASHINGTON RED-LINE HARVARD-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE CENTRAL-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE KENDALL-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE SOUTH-STATION)
  (TAKE-LINE WASHINGTON RED-LINE PARK-STREET).
 CPS: State explored: NORTH-STATION
 CPS: New operator instances:
  (TAKE-LINE NORTH-STATION GREEN-LINE BOSTON-U)
  (TAKE-LINE NORTH-STATION GREEN-LINE COPLEY-SQUARE)
  (TAKE-LINE NORTH-STATION GREEN-LINE PARK-STREET).
 CPS: State explored: STATE
 CPS: New operator instances:
  (TAKE-LINE STATE BLUE-LINE WOOD-ISLAND)
  (TAKE-LINE STATE BLUE-LINE AQUARIUM).
 CPS: State explored: WASHINGTON
 CPS: New operator instances:
  (TAKE-LINE WASHINGTON RED-LINE HARVARD-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE CENTRAL-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE KENDALL-SQUARE)
  (TAKE-LINE WASHINGTON RED-LINE SOUTH-STATION)
  (TAKE-LINE WASHINGTON RED-LINE PARK-STREET).
 CPS: State explored: HAYMARKET
 CPS: New operator instances:
  (TAKE-LINE HAYMARKET GREEN-LINE BOSTON-U)
  (TAKE-LINE HAYMARKET GREEN-LINE COPLEY-SQUARE)
  (TAKE-LINE HAYMARKET GREEN-LINE PARK-STREET).
 CPS: State explored: STATE
 CPS: New operator instances:
  (TAKE-LINE STATE BLUE-LINE WOOD-ISLAND)
  (TAKE-LINE STATE BLUE-LINE AQUARIUM).
 CPS: State explored: HARVARD-SQUARE
 CPS: New operator instances:.
 CPS: State explored: CENTRAL-SQUARE
 CPS: New operator instances:.
 CPS: Found goal state: KENDALL-SQUARE
<path KENDALL-SQUARE> 
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