a snowboarder
A person snowboarding for the first time.
Just because is person is snowboarding doesn't mean it's for the first time.
exists x1.(a_topic(x1) & n_snowboarder(x1))
exists e1 s1 x1 x2 x3.(n_time(x3) & a_first(s1) & Theme(s1,x3) & a_topic(x1) & for(e1,x3) & Actor(e1,x2) & v_snowboard(e1) & (x1 = x2) & n_person(x1))