Vulcan/TupleRepresentation

In designing output for extraction from definition sentences, it seems to me useful to use both nested and n-ary tuples.

Here are some examples to ground the discussion.

Example1:
Adaptation helps an organism survive in its environment
Pattern: X rel1 Y rel2 Z

Open IE 4.0 represents this as triples:
(adaptation; helps; organism survive in its environment)
(organism; survive; in its environment)

Should we make the nested tuple explicit:
(adaptation; helps; (organism; survive; in its environment))

Note that the nested form can be recovered from the pair of triples.

Example2:
The kidneys filter waste materials out of the blood
Pattern: X rel Y prep Z

Open IE 4.0 represents this as  an n-ary tuple:
(The kidneys; filter; waste materials; out of the blood)

Note that additional arguments in n-ary tuples always(?) begin with a
preposition.