Troops stand ready at attention.
the soldiers are digging a ditch
One cannot be digging a ditch while standing ready.
exists e1 p1 x1 x2.(at(e1,x2) & n_attention(x2) & exists s1.(Theme(s1,x1) & a_ready(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_stand(e1) & n_troops(x1))
exists e1 x1 x2.(n_soldier(x1) & Theme(e1,x2) & Actor(e1,x1) & v_dig(e1) & n_ditch(x2))