People riding horses on the beach.
Riders on horseback weaving down the coastline.
people are riders that are on horseback, the beach is a coastline
exists e1 x1 x2 x3 x4.(n_beach(x4) & a_topic(x1) & on(e1,x4) & Theme(e1,x3) & Actor(e1,x2) & v_ride(e1) & n_horse(x3) & (x1 = x2) & n_people(x1))
exists e1 s1 x1 x2 x3 x4.(n_coastline(x4) & a_topic(x1) & on(x1,x2) & a_down(s1) & Manner(e1,s1) & Theme(e1,x4) & Actor(e1,x3) & v_weave(e1) & (x2 = x3) & n_horseback(x2) & n_rider(x1))