A chef cooking at a hibachi grill.
A chef is cooking rice.
The chef could have been cooking anything, before revealing that it was rice.
exists x1 x2 x3 x4.(a_topic(x1) & at(x1,x3) & n_grill(x3) & of(x3,x4) & n_hibachus(x4) & n_cooking(x1) & of(x1,x2) & n_chef(x2))
exists p1 x1.(exists s1 x2.((x1 = x2) & n_rice(x2) & a_cooking(s1) & Theme(s1,x2)) & n_chef(x1))