People are walking the marathon for a cause.
People are jogging in the park for fun.
People cannot be walking and jogging simultaneously.
exists e1 x1 x2 x3.(n_marathon(x2) & for(e1,x3) & n_cause(x3) & Theme(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_people(x1))
exists e1 x1 x2 x3.(n_park(x2) & in(e1,x2) & for(x2,x3) & n_fun(x3) & Actor(e1,x1) & v_jog(e1) & n_people(x1))