--On 13 March 2008 19:26:54 -0700 Mark Sapiro mark@msapiro.net wrote:
- Added a new 'sibling list' feature to exclude members of another list from receiving a post from this list if the other list is in the To: or Cc: of the post or to include members of the other list if that list is not in the To: or Cc: of the post (Patch ID 1347962).
I don't understand this feature.... Hmm, Tokio Kikuchi asked about the name in 2005. I'm sorry that I didn't comment earlier.
https://sourceforge.net/tracker/?func=detail&atid=300103&aid=1347962&group_id=103
Sibling is a *completely* misleading term for this feature, because sibling relationships are necessarily symmetrical: if A is a sibling of B, then B must be a sibling of A. This feature is necessarily anti-symmetrical, more like "child" or "descendent". The term "sibling" will lead people to misconfigure their lists.
http://en.wikipedia.org/wiki/Symmetric_relation http://en.wikipedia.org/wiki/Antisymmetric_relation
Question: is the relationship also transitive? IE, if C is a child of B, and B is a child of A, then will postings to A go to members of C? If so, then the relationship should be called "descendent".
http://en.wikipedia.org/wiki/Transitive_relation
As far as inclusion is concerned, we then have a partially ordered set of mailing lists under this relationship. If the code handles the (presumably erroneous case) where a list is marked as a "sibling" of itself properly (ie, the listing should be ignored).
http://en.wikipedia.org/wiki/Partial_order
-- Ian Eiloart IT Services, University of Sussex x3148