A little boy wearing a red shirt is stooping by the water.
A boy wearing a Flash costume is on his knees by the lake.
A red shirt is not always a Flash costume.  A body of water is not always a lake.
exists e1 e2 s1 s2 x1 x2 x3 x4.(n_water(x4) & by(e2,x4) & Actor(e2,x1) & v_stoop(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_shirt(x3) & a_red(s2) & Theme(s2,x3) & (x1 = x2) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists e1 p1 x1 x2 x3 x4 x5 x6.(n_lake(x5) & n_knee(x6) & of(x6,x5) & n_male(x5) & by(p1,x5) & on(x1,x6) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_costume(x3) & (x3 = x4) & ne_nam_flash(x4) & (x1 = x2) & n_boy(x1))