Many people are sitting on the edge of a rocky beach, watching others swim in the glistening water.
There are people on the beach and swimming in the water.
"people sitting on the [...] beach" and "others swim" directly imply that there indeed are "people on the beach and swimming".
exists e2 e3 e1 s1 x1 x2 x3 x4 x5 x6 x7 x8.(n_water(x7) & of(x7,x8) & n_glistening(x8) & n_edge(x2) & on(e1,x2) & of(x2,x3) & in(e3,x7) & Theme(e3,x6) & Actor(e3,e2) & v_swim(e3) & (x3 = x6) & Theme(e2,x5) & Actor(e2,x4) & v_watch(e2) & -(x5 = x1) & n_person(x1) & n_person(x5) & n_thing(x4) & n_beach(x3) & a_rocky(s1) & Theme(s1,x3) & Actor(e1,x1) & v_sit(e1) & n_people(x1) & n_quantity(x1))
exists p1 x1 x2 x4 x5 x6.(n_water(x2) & n_swimming(x6) & n_beach(x5) & subset_of(x6,x4) & subset_of(x5,x4) & in(p1,x2) & exists x3.((x1 = x3) & on(x3,x4) & n_people(x3)))