@verb #1:"isoneof" this none this rxd #60
@program #1:"isoneof" this none this
":isoneof(x,y,z,...) = this isa x, y or z, etc."
if (!valid(parent(this)))
  return !!(this in args)
else
  return !!(this in args) || parent(this):isoneof(@args)
endif
"Last modified by Dax (#789) on Tue May  3 15:14:12 2005 MDT."
.