[SOLVED] prologTHE GARDEN PHOTOGRAPH PROBLEM

THE GARDEN PHOTOGRAPH PROBLEM

A photographer wants to take a photograph of her garden. Initially she is in her car, her camera is in her house, and the camera is switched off. The photographer can do any of the following actions:

Take a picture of the garden (provided she is in the garden holding the camera, and the camera is switched on).

Turn on the camera (provided she is holding the camera and it is switched off).

Pick up the camera (provided she is in the same place as the camera).

Go from one place (the car, the house or the garden) to another.

Put down the camera (provided she is holding the camera).

Turn off the camera (provided she is holding the camera and it is switched on).

The Garden Photograph Problem is the problem of finding a sequence of actions that the photographer can perform to end up with a photograph of her garden. (For simplicity it is assumed that the camera never runs out of memory or battery life.)

A Prolog program (see attached below) has been partially written to solve this problem. In this program the state of the photographers environment is represented by a state term in which the functor state takes five arguments as follows:

state(

Photographer_location, % house, garden or car

Camera_location, % house, garden or car

Holding_camera_or_not, % holding or notHolding

Camera_on_or_off, % on or off

Photo_taken_or_not % photoTaken or photoNotTaken

)

The possible actions of the photographer are represented with the following six terms:

takeGardenPhoto

turnOn

pickUp

go(From, To)

putDown

turnOff

The completed program will consist of definitions for the predicates place/1, can_do/3 and can_photo_garden/3. The definitions for place/1 and can_photo_garden/3 are already complete and are as follows:

place(garden).

place(house).

place(car).

can_photo_garden(state(W, X , Y, Z, photoTaken), [], States_so_far).

can_photo_garden(State, [Action|Plan_for_state_after], States_so_far):-

can_do(State, Action, State_after),

+ member(State_after, States_so_far),

can_photo_garden(State_after, Plan_for_state_after, [State_after|States_so_far]).

Complete the program by adding clauses for can_do/3 that describe the effects of each of the individual actions above. The first argument of can_do/3 represents the state before the action has been performed, the second argument is the action name, and the third argument represents the state after the action has been performed. A clause for the action takeGardenPhoto has already been added:

can_do(state(garden, garden, holding, on, Photo_taken_or_not),

takeGardenPhoto,

state(garden, garden, holding, on, photoTaken)).

The completed program should be able to produce input/output similar to the following:

?- can_photo_garden(state(car, house, notHolding, off, photoNotTaken),

Plan, [state(car, house, notHolding, off, photoNotTaken)]).

Plan = [go(car, garden), go(garden, house), pickUp, turnOn,

go(house, garden), takeGardenPhoto] ;

..

Optionally, but only once you have completed the main programming task above, you may add extra code that enhances the program in some other way(s), for example by allowing the user to input alternative starting states for the problem, or by causing plans to be output in a natural-language-style format. But do not include enhancements that involve altering the definitions of place/1, can_do/3 or can_photo_garden/3 in any way.

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