The skinny brown dog is walking on a fallen tree.
a pair of kittens attack a squirrel
The dog cannot also be a pair of kittens.  Furthermore, one cannot be both walking on a fallen tree while simultaneously attacking a squirrel.
exists e1 s1 s2 x1 x2 x3.(n_dog(x1) & a_brown(s1) & Theme(s1,x1) & of(x1,x2) & n_skinny(x2) & on(e1,x3) & n_tree(x3) & a_fallen(s2) & Theme(s2,x3) & Actor(e1,x1) & v_walk(e1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_attack(e1) & n_squirrel(x3) & of(x1,x2) & n_kitten(x2) & n_pair(x1))