Students practicing yoga in a class setting.
The students solve equations on the board.
The students can't be practicing yoga and solving equations.
exists e1 x1 x2 x3 x4 x5.(a_topic(x1) & in(e1,x4) & n_setting(x4) & of(x4,x5) & n_class(x5) & Theme(e1,x3) & Actor(e1,x2) & v_practice(e1) & n_yoga(x3) & (x1 = x2) & n_student(x1))
exists e1 x1 x2 x3.(n_board(x3) & n_student(x1) & on(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_solve(e1) & n_equation(x2))