Earlier, I wrote, "The reader expects a predicate nominative. Without it,
the clause is ontological, and BH does not use _HYH_ that way."
Actually, BH does use _HYH_ ontologically without a predicate nominative,
but only with the negative. See Exod 20:32 and Eccl 4:3. My theory is
that the writer uses _)YN_ when the tense/aspect is not important, and some
form of _L) HYH_ to make tense/aspect explicit.
If this pertains to affirmative statements mutatis mutandis, perhaps God
could have said _)NY Y$ )NY_ "I am I EXIST" if tense/aspect were not
important. That He used _HYH_ implies that tense/aspect is important.
Whether it implies present, future, habitual, or something else is,
apparently, debatable.