Today I posted the definition of FBC7. Let me post some other ones; FBC1 (the first one, also called "Weak FBC"):
Premise: V is a set of voters who have the same preferences and all vote in the same way. Everyone other than V has already voted. Requirement: By voting someone over their favorite, V can't gain an outcome that they like better than any outcome that they could get without voting someone over their favorite. [end of FBC1 definition] FBC2: Premise: Same as FBC1, plus this: The only way that V can keep Worst from winning is by getting Compromise elected instead. They have a way of voting that would accomplish that. Requirement: If V votes everyone over Worst, and doesn't vote anyone over Compromise, then Worst won't win. [end of FBC2 definition] FBC3: Premise: Same as FBC1, plus this: A and B are disjoint sets of candidates. The winner will come from A or B. V has a way of voting that will ensure that the winner won't come from B. Requirement: If V votes everyone not in B over the B candidates, and doesn't vote anyone over any of the A candidates, then the winner won't come from B. [end of FBC3 definition] FBC4: Same as FBC2, except that "...votes everyone over Worst" is replaced by "...doesn't vote Worst over anyone." And, to the requirement are added the words, "... and votes Compromise over Worst" FBC5: Same as FBC3, except that "...votes everyone not in B over the B candidates" is replaced by "Doesn't vote the B candidates over anyone. And, to the requirement, are added the words "...and votes the A candidates over the B candidates" FBC6: Same as FBC3, but the requirement only speaks of voting, over B, everyone not in B. FBC7: Moving a candidate to top of your ballot should never give the/a win to a candidate not at top on your ballot. Well, maybe it would be better to use more words: If no one other than your candidates at top wins, then moving a candidate to top on your ballot shouldn't give the/a win to a candidate not at top on your ballot.. (A candidate is at top on a ballot iff no one is ranked over hir.) [end of FBC7 definition] FBC8 (Strong FBC): Same as FBC1, but, instead of saying "...an outcome better than every...", it says "an outcome as good as even one of..." (I don't know who defined Strong FBC. It's unnecessarily demanding. ABR isn't an FBC version, but it's the mirror image of FBC7. I feel that FBC7 and ABR, adequately replace some of the FBC version. I'm not completely sure which ones I like best, but I like FBC7's simplicity. I'll probably say that "FBC", without a number qualification, should mean "FBC7". Mike Ossipoff ---- Election-Methods mailing list - see http://electorama.com/em for list info
