A boy in a pool tilts his head back.
A girl does the breaststroke.
A boy, not a girl, can't do the breaststroke while tilting his head back
exists e1 s1 x1 x2 x3.(a_back(s1) & Manner(e1,s1) & Theme(e1,x3) & Actor(e1,x1) & v_tilt(e1) & n_head(x3) & of(x3,x1) & n_male(x1) & in(x1,x2) & n_pool(x2) & n_boy(x1))
exists e1 x1 x2.(n_breaststroke(x2) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_girl(x1))