inverse proposals

["Barnhill, William [USA]" <barnhill_william@bah.com>]

Ranked options in my view:

#1 : $of,   $child$of, $parent$of,  $is$of  (Joseph and I talked about this, is his idea originally, but I like it).

#2 :  $inv, $inv$child, $inv$parent, $inv$is

#3 : $has is inverse of $is, requires much discussion, many implications