[EM] Later-no-harm definition

[Chris Benham]

Quoting  D.R. Woodall,

"Later-no-harm:  Adding a later preference to a ballot should not harm 
any candidate already listed".

In other words, if  a method meets Later-no-harm then  voters can never 
get an advantage by truncating.
It is met by IRV, but is incompatible with  Condorcet.
I got this from what I found to be the very interesting and illuminating 
paper "Monotonicity and Single-Seat Election
Rules" by Woodall, and uploaded by  Marcus Schulze:
http://groups.yahoo.com/group/election-methods-list/files/wood1996.pdf

Chris Benham