[EM] RP examples

[Elisabeth Varin/Stephane Rouillon]

> Strategy-Free Criterion (SFC)
>
> If an Ideal Democratic Winner (IDW) exists, and if a majority prefers
the IDW to another
> candidate, then the other candidate should not win if that majority
votes sincerely and no
> other voter falsifies any preferences.

Both "majority" definitions fit.
B is the IDW.
A is the other candidate.

If I understand well, you mean
"No group should be able to defeat a Condorcet winner simply by
truncating its preferences"

>Sincere preferences:
>
>100: ABC
>49:  BAC
>75:  CBA
>
>Suppose that no one falsifies a preference, and that the 49 B voters
>and the 75 C voters vote sincerely, voting all of their preferences.
>But suppose also that the 100 A voters truncate, by not ranking B.

(...and neither C)

>
>Now B is beaten by C, with a margin of 26. B beats A, with a margin
>of 49+75-100 = 24. A beats C, with a margin of 100+49-75 = 74.
>
>A's defeat margin is the least, and A wins, contrary to what SFC
>requires.

I see how Ranked Pair with winning-votes will
ensure B to still win
100: A
49:   BAC
75:   CBA

It works for this example, do you have a proof describing why it would
always work?

I will need more time to look at the other criterias...

Stephane Rouillon.