[Date Index] [Thread Index] [Author Index]

RE: selfdefined operators

• To: mathgroup at smc.vnet.net
• Subject: [mg23000] RE: [mg22989] selfdefined operators
• From: "David Park" <djmp at earthlink.net>
• Date: Mon, 10 Apr 2000 02:22:29 -0400 (EDT)
• Sender: owner-wri-mathgroup at wolfram.com

Roland Koppenberger wrote: 
> I have defined the operator \[CirclePlus] in the following way:
> 
> x_ \[CirclePlus] y_ := x y /(x + y)
> 
> When type in
> 
> 1 \[CirclePlus] 2
> 
> I get 2/3 as the right result. But when I try to compute
> 
> 1 \[CirclePlus] 2 \[CirclePlus] 3
> 
> the result will not be computed. How can I specify the operator in a
> general way?
> 

Roland,

Either use parentheses, since your function only accommodates 2 arguments:

1 \[CirclePlus] (2 \[CirclePlus] 3)

or define CirclePlus this way to accommodate more than two arguments:

CirclePlus[x_, y_] := x y/(x + y)
CirclePlus[x_, y_, z__] := CirclePlus[CirclePlus[x, y], z]

1 \[CirclePlus] 2 \[CirclePlus] 3
6/11

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/