% Tournament scheduling
% (c) 2007 Tomi Janhunen
%
% usage: lparse -c n=4 schedule.lp | smodels 0

% The number of teams n is assumed even

team(1..n).
week(1..n-1).
field(1..n/2).

hide team(T).
hide week(W).
hide field(F).

1 { schedule(W,F,T1,T2):team(T1):team(T2):T1<T2 } 1 :- week(W), field(F).

:- 2 { schedule(W,F,T1,T2):week(W):field(F) }, team(T1), team(T2), T1<T2.

:- 2 { schedule(W,F1,T,T1):field(F1):team(T1):T<T1,
       schedule(W,F2,T2,T):field(F2):team(T2):T2<T }, team(T), week(W).