sorts

   #people = {tommy, alex, john, daniel, sarah, peter, lino}.
   #gender = {male, female}.

predicates

   advisor(#people, #people).
   friend(#people, #people).
   gender(#people, #gender).
   spanish(#people).

rules

   advisor(tommy, alex).
   advisor(tommy, john).
   advisor(tommy, daniel).
   advisor(tommy, lino).
   friend(lino, alex).
   friend(lino, peter).
   friend(sarah, alex).
   gender(tommy, male).
   gender(lino, male).
   gender(sarah, female).
   spanish(lino).