A dog jumps over a chain.
A cat is sitting by a rope.
It is either a dog or a cat and can't be a chain and a rope simultaneously.
exists e1 x1 x2.(over(e1,x2) & n_chain(x2) & Actor(e1,x1) & v_jump(e1) & n_dog(x1))
exists e1 x1 x2.(by(e1,x2) & n_rope(x2) & Actor(e1,x1) & v_sit(e1) & n_cat(x1))