[EM] CDTT,IRV

[Chris Benham]

James G-A,
You wrote (Thur.May 26):

>Yes, CDTT seems like one interesting way to bring IRV toward
>Smith-efficiency. CWO-IRV is another, in my opinion.
>
I'm strongly opposed to CWO (Candidate Withdrawal Option).  If such a 
thing were proposed in Australia or  (I am sure) the UK, it would be 
strongly opposed by people
mindful of  the principles of constitutional democracy (and many 
others)  as an attempt by "politicians"/political parties to usurp the 
sovereignty of the voters.

>CDTT,IRV looks like my July 26 UMID,IRV proposal.
>
Based on various precedents, when I refer to the name of  some compound 
of  two methods (or a "social choice function" like CDTT and a method),
separating the two with a comma means to use the second to order the 
candidates and the first to pick the highest-ordered that is a winner of 
the first method.

Separating them with a double forward-slash on the other hand means to  
use  the first  to  eliminate some candidates, and then proceed with the 
second with
those eliminated candidates dropped from the ballots to pick the winner 
from those remaining.
So in my book (while  "UMID" is the same as  CDTT) your proposal was 
UMID//IRV, not  "UMID,IRV".

As I explained in an earlier message,  this difference causes UMID//IRV  
(or  CDTT//IRV)  to fail  Mono-add-Plump and Mono-append.


Chris Benham