A man waterskies.
A man is water skiing.
man waterskies. is same as man is water skiing.
exists x1 x2.(a_topic(x1) & n_watersky(x1) & of(x1,x2) & n_man(x2))
exists p1 x1.(exists x2 x3.((x1 = x2) & n_skiing(x2) & of(x2,x3) & n_water(x3)) & n_man(x1))