fix bone incrementation; some docs
==
:: $ossuary: bone<->duct bijection and .next-bone to map to a duct
::
-:: The first bone is 2, since bone 0 is reserved for nack-traces.
+:: The first bone is 0. They increment by 4, since each flow includes
+:: a bit for each message determining forward vs. backward and a
+:: second bit for whether the message is on the normal flow or the
+:: associated diagnostic flow (for nack-traces).
::
+$ ossuary
- $: next-bone=_`bone`2
+ $: =next=bone
by-duct=(map duct bone)
by-bone=(map bone duct)
==
[u.existing ossuary]
::
:- next-bone.ossuary
- :+ (add 2 next-bone.ossuary)
+ :+ (add 4 next-bone.ossuary)
(~(put by by-duct.ossuary) duct next-bone.ossuary)
(~(put by by-bone.ossuary) next-bone.ossuary duct)
::
