ex08.in

formulas(sos).

  % 1. every child loves anyone who gives the child any present.
  (all x (child(x) -> (all y (givepresent(y, x) -> love(x,y))))).

  % 2. every child will be given some present by santa if santa can travel on christmas eve.
  (all x (child(x) -> (travel(santa, xmas) -> givepresent(santa, x)))).

  % 3. it is foggy on christmas eve.
  foggy(xmas).

  % 4. anytime it is foggy, anyone can travel if he has some source of light.
  (all x (foggy(x) -> (all y (haslight(y) -> travel(y, x))))).

  % 5. any reindeer with a red nose is a source of light.
  % (anyone who has a reindeer with a red nose has a source of light)
  (all x (hasdeer(x) -> haslight(x))).

end_of_list.

formulas(goals).

  % 6. if santa has some reindeer with a red nose, then every child loves santa.
  hasdeer(santa) -> (all x (child(x) -> love(x, santa))).

end_of_list.