A boy reads a book.
The boy is reading.
Reads a book is a type of reading.
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_read(e1) & n_book(x2) & n_boy(x1))
exists e1 x1 x2.(n_boy(x1) & Theme(e1,x2) & Actor(e1,x1) & v_read(e1) & n_thing(x2))