A man is working on an art piece.
The man is an artist.
An artist is someone who creates art, and the man is working on an art piece, so it can be said that the man is an artist.
exists e1 x1 x2 x3.(on(e1,x2) & n_piece(x2) & of(x2,x3) & n_art(x3) & Actor(e1,x1) & v_work(e1) & n_man(x1))
exists p1 x1.(n_man(x1) & exists x2.((x1 = x2) & n_artist(x2)))