The man is welding the iron.
An artist is sculpting an iron sculpture.
That one is an artist cannot be inferred from the fact that one is welding iron.
exists e1 x1 x2.(n_iron(x2) & n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_weld(e1))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_sculpt(e1) & n_sculpture(x2) & of(x2,x3) & n_iron(x3) & n_artist(x1))