[EM] RP & Schwartz set

[Markus Schulze]

Dear Mike,

you wrote (12 Mar 2002):
> What I said was that Tideman can choose outside the initial
> Schwartz set. The situations where it will do that require pair-ties,
> and Tideman makes its choice outside the initial Schwartz set when
> it solves a tie, where the Tideman procedure leaves 2 candidates
> undefeated. My example in which Tideman chooses outside the initial
> Schwartz set doesn't have any equal defeats.

Could you please post a concrete example where Tideman chooses
decisively outside the Schwartz set?

You wrote (12 Mar 2002):
> Markus wrote (12 Mar 2002):
> > Actually, when all Schwartz winners are ranked ahead of
> > all other candidates in the TBRC, then Tideman never
> > chooses decisively or randomly a candidate who is not
> > in the Schwartz set.
>
> What you're saying is that it's possible to write a class of examples
> in which Tideman won't choose outside of the initial Schwartz set.
> That doesn't contradict my statement that Tideman can choose outside
> the initial Schwartz set.

Actually no. What I say is that when you choose the TBRC in such
a manner that all Schwartz winners are ranked ahead of all other
candidates then Tideman never chooses decisively or randomly
outside the Schwartz set.

You wrote (12 Mar 2002):
> What's the TBRC? Transitive B_____ Ranking of Candidates? The
> ordering of candidates that's consistent with the defeats kept by
> the Tideman procedure?

The TBRC (= Tiebreaking Ranking of Candidates) says to whose favour
indecisive situations are resolved.

Markus Schulze