Blocks World in prolog

[steven890]

I try to solve the blocks world prolbem in prolog but i a, facing some difficulties ani I need your help.
Firstly I do not know how to print the current situation of the blocks for example
b
a c d
=====
and secondly how can i change the programm in order the user to be able to give the initial state.
Thanks in advance

 

[joel76]

b
a c d
=====
How do you managed this situation in your code ?

It's the same for the second question.

 

[steven890]

i use on(b,a) which means b is above a.
and on(c,table) which means c is on table.
I follow the same for the other blocks.

 

[joel76]

OK.
You can build a list of boxes piled [[b, a, table], [c, table], [d, table]], you get the lenght of the highest one, and then you can print the situation.

 

[steven890]

and how can i make it in order the initial situation to be given from the user?

 

[joel76]

If I have understood your request (!?) I think this is technical so I give you my solution in SWI-Prolog :

:- dynamic (on/2).

get_car(In, Out) :-
	atom_codes(Out, [In]).


set(B) :-
	format('On which object is the block ~w ? ', [B]),
	read(X),
	assert(on(B, X)).

test :-
	write('How many blocks ? '), read(X),
	Max is 96 + X,
	numlist(97, Max, L),
	maplist(get_car, L, L1),
	maplist(set, L1).