"In my opinion, nobody has even approached valid definitions"
Been defined internationally since 1954 and had sever hundred books published based on that definition - may not satisfy you Jim, but until someone comes up with a better one, we'll just have to struggle on with the one we've got - that is, if we intend trying to pass on what we've got.
Bit to wet to start burning the books in the garden at the present time.
Jim Carroll