The mountain biker in blue rides down a rocky path.
The mountain biker is riding down a rocky path on a sunny day.
The fact that a mountain biker is riding doesn't imply that it's a sunny day.
exists s1 s2 x1 x2 x3 x4.(n_biker(x1) & of(x1,x2) & n_mountain(x2) & a_topic(x1) & in(x1,x3) & down(x3,x4) & n_path(x4) & a_rocky(s2) & Theme(s2,x4) & n_ride(x3) & a_blue(s1) & Theme(s1,x3))
exists e1 s1 s2 s3 x1 x2 x3 x4.(n_biker(x1) & of(x1,x2) & n_mountain(x2) & on(e1,x4) & n_day(x4) & a_sunny(s3) & Theme(s3,x4) & a_down(s2) & Manner(e1,s2) & Theme(e1,x3) & Actor(e1,x1) & v_ride(e1) & n_path(x3) & a_rocky(s1) & Theme(s1,x3))