I am really not sure what this group is doing.
What is happening is obvious.
not sure is not the same as obvious
exists x1 x3.(n_group(x3) & n_person(x1) & -exists e1 s1 s2 x2.(n_thing(x2) & a_really(s2) & Manner(s1,s2) & Theme(s1,x2) & Actor(s1,x1) & a_sure(s1) & Theme(e1,x2) & Actor(e1,x3) & v_do(e1)))
exists e1 s1 x1.(n_thing(x1) & Theme(s1,x1) & a_obvious(s1) & Actor(e1,x1) & v_happen(e1))