[EM] mutual majority set

[Kristofer Munsterhjelm]

Kevin Venzke wrote:
> Hi Kristofer,
> 
> --- En date de : Lun 7.2.11, Kristofer Munsterhjelm <km-elmet at broadpark.no> a écrit :

>> Is that the same as the CDTT set? The CDTT set is like the
>> Schwartz set, but the relation is "beats by a majority"
>> rather than just "beats". You could make a ranking of sets
>> by first having the top set, then the top set with these
>> excluded, then the top set with those excluded, and so on.
> 
> This is more similar to Smith and CGTT than Schwartz and CDTT. As far
> as I know you can't define the latter two with the wording "the (one and
> only) smallest set that beats everyone outside the set." You have to
> either use beatpaths in the definition or else speak of the "union of
> all minimal non-empty subsets that don't lose to anyone outside."

According to the Electorama wiki, the CDTT set is "the union of all 
minimal nonempty sets of candidates such that no candidate in each set 
has a majority-strength pairwise loss to any candidate outside of the 
set". That sounds more like the Schwartz set (union of minimal nonempty 
sets) than the Smith set (smallest set that beats all outside it).

Is the wiki wrong? I haven't investigated CDTT in detail, but it seemed 
similar.