A group of snowmobile riders gather in the snow.
People in shorts are playing tennis.
If they are gathered in snow they are not playing tennis.
exists e1 s1 x1 x2 x3.(n_snow(x3) & in(e1,x3) & Actor(e1,x1) & v_gather(e1) & of(x1,x2) & n_rider(x2) & a_snowmobile(s1) & Theme(s1,x2) & n_group(x1))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_tennis(x3) & in(x1,x2) & n_shorts(x2) & n_people(x1))