docs: federation: the fractions are numbers, a decision can be refused

What the maintainer answered to the design's last two questions, and
what follows from it:

* The fractions are numbers of the policy like the others, changed by
  a decision to any value: the share of the voters present a decision
  takes (two thirds recommended), the share of all of them (half), and
  the share whose stamps make the swarm's time and a user gone (a
  third). What is promised of decisions is argued for the recommended
  ones; Why it holds says what other values carry.
* Refusing a decision: a node follows every decision that counts
  unless its operator has it refuse, by bounds on the policy's numbers
  or by hand. It then moves to the epoch built at the decision's
  history without it, which is the same for every node that refuses
  the same decision: those who think alike go on together without
  arranging it. While a proposal's votes run, a node whose bounds it
  breaks says so. A remake or a change of policy is refused by
  staying.
* A decision gives a user name with its namespace, as designed.
* No open question is left. The options not taken that the questions
  listed are among the roads not taken: first users voting as soon as
  created, voters let in without a remake, other reaches of an
  unvouch, a gone user coming back, first keys by those who vouch,
  a registry of only what is signed, numbers the design fixes.

The attacks are 78; the stages name them by their numbers.

future-work.md: bounds on more than numbers.

0 files changed, 0 insertions, 0 deletions