assign(domain_size,4).
assign(max_models,-1).

list(distinct).
  [ross, chandler, monica, rachel].
end_of_list.

formulas(married).
   all x (married(x)  <->  m(x)).
   m(ross)     <-> (married(rachel) -> -married(ross)).
   m(rachel)   <-> -married(chandler).
   m(monica)   <-> (married(monica) & married(chandler)).
   m(chandler) <-> -m(monica).
end_of_list.
