People are sitting on a snowy mountain.
People are sitting on a hot desert sand dune.
The people cannot be on a mountain and on a sand dune simultaneously
exists e1 s1 x1 x2.(on(e1,x2) & n_mountain(x2) & a_snowy(s1) & Theme(s1,x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1))
exists e1 s1 x1 x2 x3 x4.(on(e1,x2) & n_dune(x2) & of(x2,x4) & n_sand(x4) & of(x2,x3) & n_desert(x3) & a_hot(s1) & Theme(s1,x2) & Actor(e1,x1) & v_sit(e1) & n_people(x1))