A group of parents and children strapped in safety helmets ride their bikes down a path.
A family goes out for their first bike ride as a group.
Parents and children together might not be part of one family.  A group riding bikes together aren't necessarily on their first bike ride.
exists e2 e1 x1 x2 x3 x4 x5 x6 x7 x8 x9.(down(e2,x9) & n_path(x9) & Theme(e2,x8) & Actor(e2,x1) & v_ride(e2) & n_bike(x8) & of(x8,x1) & n_thing(x1) & in(e1,x6) & n_helmet(x6) & of(x6,x7) & n_safety(x7) & Theme(e1,x5) & v_strap(e1) & (x1 = x5) & of(x1,x2) & n_child(x4) & n_parent(x3) & subset_of(x4,x2) & subset_of(x3,x2) & n_group(x1))
exists e1 s1 s2 x1 x2 x3 x4.(for(e1,x2) & as(x2,x4) & n_group(x4) & n_ride(x2) & of(x2,x3) & n_bike(x3) & a_first(s2) & Theme(s2,x2) & of(x2,x1) & n_thing(x1) & a_out(s1) & Manner(e1,s1) & Actor(e1,x1) & v_go(e1) & n_family(x1))