[EM] MinMax variant

[Markus Schulze]

I wrote (8 March 2003):
> Steve Eppley wrote (7 March 2003):
> > Minimax(pairwise opposition) even satisfies a criterion promoted by
> > some advocates of Instant Runoff, which I call "Uncompromising":
> >
> >    Let w denote the winning alternative given some set
> >    of ballots.  If one or more ballots that had only w
> >    higher than bottom are  changed so some other
> >    "compromise" alternative x is raised to second
> >    place (still below w but raised over all the other
> >    alternatives) then w must still win.
> >
> > The proof that Minimax(pairwise opposition) satisfies Uncompromising
> > is simple:  Raising x increases the pairwise opposition for all
> > candidates except w and x, and does not decrease the pairwise
> > opposition for any candidate, so w must still have the smallest
> > maximum pairwise opposition.
> >
> > That criterion can be strengthened somewhat and still be satisfied:
> > Changing pairwise indifferences to strict preferences in ballots that
> > ranked w top cannot increase w's pairwise opposition or decrease any
> > other alternatives' pairwise opposition.
>
> That sounds like Woodall's later-no-harm + later-no-help.

Sorry. Eppley's Uncompromising seems to be only Woodall's later-no-harm:
http://groups.yahoo.com/group/single-transferable-vote/files/Woodall_Monotonicity_DAM_1997.pdf

Markus Schulze