The man is fishing at the water's edge.
A man is swimming in the middle of a lake.
One is either fishing or swimming, he can't do both simulteanously
exists e1 x1 x2 x3.(n_edge(x3) & of(x3,x2) & n_water(x2) & n_man(x1) & at(e1,x3) & Actor(e1,x1) & v_fish(e1))
exists e1 x1 x2 x3.(n_middle(x2) & in(e1,x2) & of(x2,x3) & n_lake(x3) & Actor(e1,x1) & v_swim(e1) & n_man(x1))