Many people are sitting around computers.
A group is running a marathon.
People cannot be running and sitting simultaneously.
exists e1 x1 x2.(around(e1,x2) & n_computer(x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1) & n_quantity(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_run(e1) & n_marathon(x2) & n_group(x1))