Re: Does Union[] reliably sort?
- To: mathgroup at smc.vnet.net
- Subject: [mg123706] Re: Does Union[] reliably sort?
- From: Shizu <slivo.vitz at msa.hinet.net>
- Date: Fri, 16 Dec 2011 05:46:46 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Mathematically, we don't sort a collection of elements to make it a set. For computational purposes, sorted sets are easier to compare. And Mathematica tries to put an expression (say, a set) into a standard (sorted) form during evaluation. The question of "reliability" depends on what we do with the list. Sets are just a special case of lists in Mathematica. Search "guide/ListManipulation" for functions on lists.