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zkessin/poset.pl

Last active August 29, 2015 14:02
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Code for partially ordered sets in prolog
Raw
poset.pl
connected(A,B) :-
edge(A,B).
sib(A,B) :-
path(C,A,_),
path(C,B,_),
\+path(A,B,_),
\+path(B,A,_).
ancestor(A,B) :-
path(A,B,_).
descendent(A,B) :-
path(B,A,_).
path(A,B,Path) :-
travel(A,B,[A],Q),
reverse(Q,Path).
travel(A,B,P,[B|P]) :-
connected(A,B).
travel(A,B,Visited,Path) :-
connected(A,C),
C \== B,
\+member(C,Visited),
travel(C,B,[C|Visited],Path).
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