A brown dog is walking down steps.
A dog runs across the field.
If the dog is runnning across the field, that dog cannot be walking down steps at the same time.
exists e1 s1 s2 x1 x2.(a_down(s2) & Manner(e1,s2) & Theme(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_step(x2) & n_dog(x1) & a_brown(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_field(x2) & across(e1,x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1))