Custom sort a list of pairs

*To*: mathgroup at smc.vnet.net*Subject*: [mg73633] Custom sort a list of pairs*From*: planetmarshalluk at hotmail.com*Date*: Fri, 23 Feb 2007 04:41:55 -0500 (EST)

Hi there, I've searched through existing posts to no avail, what I want to do is this: Sort a nested list of pairs, so that each pair is sorted by reverse canonical order on its first element, and in normal order on its second element. For example, I want some function sortPairs[items_] that when given the input {{ 1,a},{2,a},{3,a},{1,b},{2,b},{1,c}} produces the output {{3,a},{2,a},{2,b}{1,a},{1,b},{1,c}} Any help much appreciated. Thanks, Andrew

**Follow-Ups**:**Re: Custom sort a list of pairs***From:*János <janos.lobb@yale.edu>