On garden lawn, black dog is retriving an object.
A black dog is playing fetch outside.
Just because it is  On garden lawn, black dog is retriving an object does not mean it is outside.
exists e1 s1 x1 x2 x3 x4.(on(e1,x3) & n_lawn(x3) & of(x3,x4) & n_garden(x4) & Theme(e1,x2) & Actor(e1,x1) & v_retrive(e1) & n_object(x2) & n_dog(x1) & a_black(s1) & Theme(s1,x1))
exists e1 s1 s2 s3 x1.(a_outside(s3) & Manner(e1,s3) & a_fetch(s2) & Manner(e1,s2) & Actor(e1,x1) & v_play(e1) & n_dog(x1) & a_black(s1) & Theme(s1,x1))