Two young fair girls are smiling a posing together while they ride in a boat wearing floatation vests.
The girls are sisters.
Two young fair girls are not necessarily sisters.
exists e1 p1 s1 s2 s3 x1 x2.(exists e3 e2 x3 x4 x5 x6.(in(e2,x3) & Theme(e3,x5) & Actor(e3,x4) & v_wear(e3) & n_vest(x5) & of(x5,x6) & n_floatation(x6) & (x3 = x4) & n_boat(x3) & Actor(e2,x1) & v_ride(e2)) & n_thing(x1) & while(e1,p1) & a_together(s3) & Manner(e1,s3) & Theme(e1,x2) & Actor(e1,x1) & v_smile(e1) & n_pose(x2) & n_girl(x1) & a_fair(s2) & Theme(s2,x1) & a_young(s1) & Theme(s1,x1) & card_eq_2(x1))
exists p1 x1.(n_girl(x1) & exists x2.((x1 = x2) & n_sister(x2)))