A man is skiing in water.
A man is skiing.
skiing in water is same as skiing.
exists e1 x1 x2.(in(e1,x2) & n_water(x2) & Actor(e1,x1) & v_ski(e1) & n_man(x1))
exists p1 x1.(exists x2.((x1 = x2) & n_skiing(x2)) & n_man(x1))