formulas(sos). all p (Proposition(p)->Proposition(NEG(p))). all d all p (Point(d)&Proposition(p)-> (True(NEG(p),d)<-> -True(p,d))). all x (Situation(x)->Object(x)). all x (Object(x)-> (Possible(x)<->Situation(x)& (exists y (Point(y)& (all p (Proposition(p)-> (TrueIn(p,x)->True(p,y)))))))). all x (Object(x)-> (Consistent(x)<->Situation(x)& -(exists p (Proposition(p)&TrueIn(p,x)&TrueIn(NEG(p),x))))). end_of_list.