A rollerblader is skating against the flow of many other rollerbladers.
A rollerblader is moving with the crowd.
Moving against the flow doesn't mean moving with.
exists e1 x1 x2 x3.(n_flow(x2) & against(e1,x2) & of(x2,x3) & -(x3 = x1) & n_rollerblader(x1) & n_rollerblader(x1) & n_rollerblader(x3) & n_quantity(x3) & Actor(e1,x1) & v_skate(e1))
exists e1 x1 x2.(n_crowd(x2) & with(e1,x2) & Actor(e1,x1) & v_move(e1) & n_rollerblader(x1))