The dogs are joined together with a red harness.
Two dogs are harnessed together.
First sentence does not specify two dogs on the harness, only that there are multiple dogs.
exists e1 s1 s2 x1 x2.(n_dog(x1) & with(e1,x2) & n_harness(x2) & a_red(s2) & Theme(s2,x2) & a_together(s1) & Manner(e1,s1) & Theme(e1,x1) & v_join(e1))
exists e1 s1 x1.(a_together(s1) & Manner(e1,s1) & Theme(e1,x1) & v_harness(e1) & n_dog(x1) & card_eq_2(x1))