A swan is above water.
A big swan is above water.
There is know indication of how big the swan is.
exists p1 x1.(exists s1 x2.((x1 = x2) & n_water(x2) & a_above(s1) & Theme(s1,x2)) & n_swan(x1))
exists p1 s1 x1.(exists s2 x2.((x1 = x2) & n_water(x2) & a_above(s2) & Theme(s2,x2)) & n_swan(x1) & a_big(s1) & Theme(s1,x1))