The boy in the yellow shirt is skipping stones.
The rocks are skipping across the water.
Rocks and stones are not the same thing. The stones may not be successfully skipping across water.
exists e1 s1 x1 x2 x3.(n_shirt(x2) & a_yellow(s1) & Theme(s1,x2) & n_boy(x1) & Theme(e1,x3) & Actor(e1,x1) & v_skip(e1) & n_stone(x3) & in(x1,x2))
exists e1 x1 x2.(n_water(x2) & n_rock(x1) & across(e1,x2) & Actor(e1,x1) & v_skip(e1))