A group of people are standing in the sand.
Some people are sitting indoors.
One cannot be sitting and standing simultaneously. There is not usually sand located indoors.
exists e1 x1 x2 x3.(n_sand(x3) & in(e1,x3) & Actor(e1,x1) & v_stand(e1) & of(x1,x2) & n_people(x2) & n_group(x1))
exists p1 x1.(exists e1 x2.((x1 = x2) & n_indoor(x2) & Actor(e1,x2) & v_sit(e1)) & n_people(x1))