A woman dressed as a mermaid for an event.
a man dresses as a mermaid
A man and a woman are not the same.
exists e1 x1 x2 x3.(for(e1,x3) & n_event(x3) & as(e1,x2) & n_mermaid(x2) & Theme(e1,x1) & v_dress(e1) & n_woman(x1))
exists e1 x1 x2.(as(e1,x2) & n_mermaid(x2) & Actor(e1,x1) & v_dress(e1) & n_man(x1))