A dad and a son enjoying a bike ride in a nice sunny day.
A dad and a son is enjoying themselves.
If people are enjoying an activity then they are enjoying themselves.
exists e1 s1 s2 s3 x1 x2 x3 x4 x5 x6.(a_topic(s1) & subset_of(x2,s1) & Theme(e1,x4) & Actor(e1,x3) & v_enjoy(e1) & in(x4,x6) & n_day(x6) & a_sunny(s3) & Theme(s3,x6) & a_nice(s2) & Theme(s2,x6) & n_ride(x4) & of(x4,x5) & n_bike(x5) & (x2 = x3) & n_son(x2) & subset_of(x1,s1) & n_dad(x1))
exists e1 x1 x2 x3 x4.(n_group(x4) & Theme(e1,x4) & Actor(e1,x1) & v_enjoy(e1) & subset_of(x3,x1) & n_son(x3) & subset_of(x2,x1) & n_dad(x2))