A man is skiing in water.
The lake is completely frozen over.
He cannot be skiing on a frozen lake.
exists e1 x1 x2.(in(e1,x2) & n_water(x2) & Actor(e1,x1) & v_ski(e1) & n_man(x1))
exists e1 s1 x1.(n_lake(x1) & a_completely(s1) & Manner(e1,s1) & over(e1,x1) & v_freeze(e1))