% Source: http://www.cs.bgu.ac.il/cgi-bin/genaim/TerminWeb/term_check?example=sameleaves
% by: Bart Demoen <bmd@cs.kuleuven.ac.be>

sameleaves(leaf(L),leaf(L)) .
sameleaves(tree(T1,T2),tree(S1,S2)) :-
	getleave(T1,T2,L,T) ,
	getleave(S1,S2,L,S) ,
	sameleaves(T,S) .

getleave(leaf(A),C,A,C) .
getleave(tree(A,B),C,L,O) :- getleave(A,tree(B,C),L,O) .