Protesters assemble to promote the clean air act.
All the protesters know eachother.
Just because protesters assemble doesn't necessarily mean they know each other.
exists e1 p1 s1 x1 x2 x3.(n_act(x2) & of(x2,x3) & n_air(x3) & a_clean(s1) & Theme(s1,x2) & Topic(e1,p1) & Actor(e1,x1) & v_assemble(e1) & exists e2.(Theme(e2,x2) & Actor(e2,x1) & v_promote(e2)) & n_protester(x1))
exists x2.(n_protester(x2) & all x1.((x1 = x2) -> exists e1 x3.(Theme(e1,x3) & Actor(e1,x1) & v_know(e1) & n_eachother(x3))))