"As Rob says when is something really abstract? Don't think it matters, as long people can feel free to contribute to this thread."
Agree 100%, John; the question wasn't about what's permissible, but what we actually mean when we bandy about these easy definitions.
The longer I stay with this site the broader I see definitions become. If I stay long enough, perhaps I will reach a moment when no definitions exist, and everthing is everything to all people. Moment of (or for?) instantaneous combustion?
;-)
Rob C
P.S. I like your picture, by the way, Feels sort of pastoral in the sense of wheat, but no idea what I am really seeing, and that's the best way!