A skier is skiing alone in fresh powder on a sunny day.
A skier is not skiing alone
You can't be skiing alone and then be skiing alone.
exists e1 s1 s2 s3 x1 x2 x3.(on(e1,x3) & n_day(x3) & a_sunny(s3) & Theme(s3,x3) & in(e1,x2) & n_powder(x2) & a_fresh(s2) & Theme(s2,x2) & a_alone(s1) & Manner(e1,s1) & Actor(e1,x1) & v_ski(e1) & n_skier(x1))
exists x1.(-exists e1 s1.(a_alone(s1) & Manner(e1,s1) & Actor(e1,x1) & v_ski(e1)) & n_skier(x1))