a group of children are standing outside a building.
Boys get ready to play in a yard.
Not all groups of children are boys. Standing outside a building doesn't automatically mean they're going to play in a yard. Not all areas outside a building can be called a yard.
exists e1 x1 x2 x3.(outside(e1,x3) & n_building(x3) & Actor(e1,x1) & v_stand(e1) & of(x1,x2) & n_child(x2) & n_group(x1))
exists e1 p1 x1.(exists p2 s1.(Topic(s1,p2) & Actor(s1,x1) & a_ready(s1) & exists e2 x2.(in(e2,x2) & n_yard(x2) & Actor(e2,x1) & v_play(e2))) & Topic(e1,p1) & Actor(e1,x1) & v_get(e1) & n_boy(x1))