Two groups of swimmers wade out.
two groups of swimmers are competing
Just because the swimmers are in separate groups, that does not mean they are competing.
exists e1 s1 x1 x2.(a_out(s1) & Manner(e1,s1) & Actor(e1,x1) & v_wade(e1) & of(x1,x2) & n_swimmer(x2) & n_group(x1) & card_eq_2(x1))
exists e1 x1 x2.(Actor(e1,x1) & v_compete(e1) & of(x1,x2) & n_swimmer(x2) & n_group(x1) & card_eq_2(x1))