[EM] sequential dropping

[Chris Benham]

Marcus,

I  understand that what is usually meant  by  "monotonicity" is what 
Woodall calls "Mono-raise".

" Mono-raise: a candidate x should not be harmed if x is raised on some 
ballots without changing the orders of the other candidates."
On the other hand, what you refer to here is not Mono-raise but is 
instead what Woodall calls "Mono-add-top".

> /SD chooses candidate A. /  / Act II: // If "DE 19" is changed to "DE 
> 10" then SD chooses // candidate D. /

"Mono-add-top: a candidate x should not be harmed if further ballots are 
added that have x top (and are otherwise arbitrary)."

You have just done the operation back-to-front. Woodall writes that we 
can't have all three of  his Plurality property, Condorcet(Net)
and  Mono-add-top.
Mono-add-top is met by IRV, but is failed by all fashionable  and (IMHO) 
reasonable  Condorcet methods.

Chris Benham

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