Telephone wires are visible.
The telephone wires are invisible.
Visible and invisible are two different things.
exists s1 x1 x2.(Theme(s1,x1) & a_visible(s1) & n_wire(x1) & (x1 = x2) & ne_nam_telephone(x2))
exists s1 x1 x2.(n_wire(x1) & of(x1,x2) & n_telephone(x2) & Theme(s1,x1) & a_invisible(s1))