a brown and white dog jumping on a sandy beach
Dogs jumping to catch a ball on a beach.
Dog implies a singular dog, dogs mean that there are more than one.  The dogs could be jumping on the sandy beach for any reason and no mention is made of a ball, therefore it is impossible to infer that the dogs jump on a sandy beach to catch a ball.
exists e1 s1 s2 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & n_beach(x3) & of(x3,x4) & n_sandy(x4) & Actor(e1,x2) & v_jump(e1) & (x1 = x2) & n_dog(x1) & a_white(s2) & Theme(s2,x1) & a_brown(s1) & Theme(s1,x1))
exists e1 p1 x1 x2.(a_topic(x1) & Topic(e1,p1) & Actor(e1,x2) & v_jump(e1) & exists e2 x3 x4.(on(e2,x4) & n_beach(x4) & Theme(e2,x3) & Actor(e2,x2) & v_catch(e2) & n_ball(x3)) & (x1 = x2) & n_dog(x1))