A children with a helmet riding his bicycle.
Someone is outside.
Someone refers to any person of any age, a child refers to a young adolescent, and children refers to multiple kids.
exists e1 x1 x2 x3 x4.(a_topic(x1) & with(x1,x2) & Theme(e1,x4) & Actor(e1,x3) & v_ride(e1) & n_bicycle(x4) & of(x4,x1) & n_male(x1) & (x2 = x3) & n_helmet(x2) & n_child(x1))
exists s1 x1.(Theme(s1,x1) & a_outside(s1) & n_person(x1))