The dog walks on the high plank.
a cat sits snoozily
A dog is not a cat.  An animal cannot walk while it is sitting.
exists e1 s1 x1 x2.(n_plank(x2) & a_high(s1) & Theme(s1,x2) & n_dog(x1) & on(e1,x2) & Actor(e1,x1) & v_walk(e1))
exists e1 s1 x1.(a_snoozily(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1) & n_cat(x1))