strictly speaking, <> could be implemented with no help
from rc (and more generally) as in
boxredir fdin fdout cmd
okay, that's a bit silly, but the point between essential and
non-essential is in the eye of the beholder.
odd digression:
in the late 60s the fad was to rewrite bigger instruction sets in
terms of smaller ones (the metric was # of instructions). somebody
had a 16 instruction set that someone else reimplemented in 8
instructions. the apollo guidance computer had 12 instructions and
a few magic memory locations. it was finally determinted you could get by on
one instruction --- some variation on predecrement and branch
if negative. "look ma, no instructions." unfortunately, this machine
was somewhat difficult to program
- erik
