A child swims with a woman.
A child does the backstroke.
Because someone is swimming doesn't mean they are doing the backstroke.
exists e1 x1 x2.(with(e1,x2) & n_woman(x2) & Actor(e1,x1) & v_swim(e1) & n_child(x1))
exists e1 x1 x2.(n_backstroke(x2) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_child(x1))