Re: Re: operators for relations in sets

*To*: mathgroup at smc.vnet.net*Subject*: [mg60430] Re: [mg60407] Re: operators for relations in sets*From*: Andrzej Kozlowski <andrzej at yhc.att.ne.jp>*Date*: Fri, 16 Sep 2005 03:49:15 -0400 (EDT)*References*: <200509131007.GAA09833@smc.vnet.net> <dg8kar$qiq$1@smc.vnet.net> <200509150916.FAA15880@smc.vnet.net>*Reply-to*: Andrzej Kozlowski <andrzej at akikoz.net>*Sender*: owner-wri-mathgroup at wolfram.com

On 15 Sep 2005, at 18:16, Paul Abbott wrote: > In article <dg8kar$qiq$1 at smc.vnet.net>, > Andrzej Kozlowski <akoz at mimuw.edu.pl> wrote: > > >> First of all, \[SubsetEqual] is not defined in Mathematica. You can >> define your own function SubsetEqual as: >> >> SubsetEqual[A_List, B_List] := Intersection[A, B] == A >> >> so that >> >> SubsetEqual[{1},{1,2}] >> >> True >> >> etc. If you really want with the help of the Notation package you can >> make the infix form A\[SubsetEqual]B equivalent to Subsetequal[A,B] >> (although i would not bother). >> > > Actually, there is no need to use the Notation package. The infix form > {A}\[SubsetEqual]{B} _is_ interpreted automatically as SubsetEqual > [A,B]. > > Cheers, > Paul > Indeed, and this is very nice. Presumably only works for symbols that are undefined "operators" (e.g. the Operators in the palette CompleteCharacters) and for other symbols which are not officially "operators" one would have to use the Notation package? Andrzej Kozlowski

**References**:**operators for relations in sets***From:*"hawkmoon269" <rson@new.rr.com>

**Re: operators for relations in sets***From:*Paul Abbott <paul@physics.uwa.edu.au>