a man walks across the tightrope.
a ballerina performs a dance
A man cannot be a ballerina which is a female. One who walks across a tightrope cannot also be performing a dance.
exists e1 x1 x2.(n_tightrope(x2) & across(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_man(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_perform(e1) & n_dance(x2) & n_ballerina(x1))