A man in a dark shirt and pants riding a tall bicycle.
A guy is riding a bike with friends.
There is no information about who he is with - not necessarily with friends.
exists e1 s1 s2 x1 x2 x3 x4 x5 x6.(a_topic(x1) & in(x1,x2) & subset_of(x4,x2) & Theme(e1,x6) & Actor(e1,x5) & v_ride(e1) & n_bicycle(x6) & a_tall(s2) & Theme(s2,x6) & (x4 = x5) & n_pants(x4) & subset_of(x3,x2) & n_shirt(x3) & a_dark(s1) & Theme(s1,x3) & n_man(x1))
exists e1 x1 x2 x3.(with(e1,x3) & n_friend(x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & n_guy(x1))