%%% 28 NOVEMBRE 2006

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%%% There are M (max_people) people X in {1,2,...,M}
%%% Each of them at the beginning owns 2X Euros
%%% The goal is to obtain an equilibrium situation
%%% where the main difference between richness is 1
%%% Person X can donate to another person exactly
%%% X euros per action.
%%% No one can remain without money (at any state)
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max_people(5).

person(X) :- max_people(N), interval(X,1,N).


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fluent(possiede(B),1,M):- person(B),
     max_people(N),M is N*(N+1).

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action(regala(X,Y)):-
       person(X),person(Y),neq(X,Y).

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executable(regala(X,Y),[possiede(X) gt X ]) :-
        action(regala(X,Y)).

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causes(regala(X,Y), possiede(X) eq possiede(X)^(-1) - X, []):-
        action(regala(X,Y)).
causes(regala(X,Y), possiede(Y) eq possiede(Y)^(-1) + X, []) :-
        action(regala(X,Y)).

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:- dynamic(caused/2).

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initially(possiede(X) eq  2*X) :-
    person(X).

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goal(possiede(X) leq possiede(Y) + 1) :-
     person(X), person(Y), neq(X,Y).

always(possiede(1)+possiede(2)+possiede(3)+possiede(4)+possiede(5) eq 30).

%cross_constraint(possiede(1) @ 2 eq 7).


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