A man in a blue shirt is cooking hamburgers on a grill.
A man is cooking on a large propane grill.
A man does not have to wear a blue shirt, cook hamburgers, or use a propane grill.
exists p1 s1 x1 x2.(exists s2 x3 x4.((x1 = x3) & on(x3,x4) & n_grill(x4) & n_hamburger(x3) & a_cooking(s2) & Theme(s2,x3)) & in(x1,x2) & n_shirt(x2) & a_blue(s1) & Theme(s1,x2) & n_man(x1))
exists e1 s1 x1 x2 x3.(on(e1,x2) & n_grill(x2) & of(x2,x3) & n_propane(x3) & a_large(s1) & Theme(s1,x2) & Actor(e1,x1) & v_cook(e1) & n_man(x1))