Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.soft-sys.math.mathematica > #3559 > unrolled thread

Re: Unwanted Recursion

Back to article view | Back to comp.soft-sys.math.mathematica

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  Re: Unwanted Recursion DrMajorBob <btreat1@austin.rr.com> - 2011-07-07 11:48 +0000
    Re: Unwanted Recursion Kambis Veschgini <k.veschgini@thphys.uni-heidelberg.de> - 2011-07-08 08:58 +0000

#3559 — Re: Unwanted Recursion

ClearAll@p
SetAttributes[p, {Flat, OneIdentity}]
p[a_] := a
p[a]

a

Bobby

On Wed, 06 Jul 2011 04:39:33 -0500, Casorati <casorati@f-m.fm> wrote:

> I'm trying to define an anti-commutative algebra in Mathematica.
> Here I will show only a minimal example to demonstrate my point.
> The product of two elements a^b should be give by p[a,b] so I
> make p flat:
>
> SetAttributes[p, {Flat}]
>
> But now I want p[a] to reduce to a.
> Such a  rule would make other rules much simpler but when I define
>
> p[a_] := a
>
> the expression p[a] causes an infinite recursion. I get the message
>
> $IterationLimit::itlim: Iteration limit of 4096 exceeded.
>
> I have similar problems with p[]:=1 which makes mathematica puts
> ones into the p : p[a]=p[a,a]=p[1,1,...,a] .
>
> How can I solve this problem?
>
>


-- 
DrMajorBob@yahoo.com

[toc] | [next] | [standalone]

#3571

On 2011-07-07 13:48:07 +0200, DrMajorBob said:

> ClearAll@p
> SetAttributes[p, {Flat, OneIdentity}]
> p[a_] := a
> p[a]
> 
> a
> 
> Bobby
> 
> On Wed, 06 Jul 2011 04:39:33 -0500, Casorati <casorati@f-m.fm> wrote:
> 
>> I'm trying to define an anti-commutative algebra in Mathematica.
>> Here I will show only a minimal example to demonstrate my point.
>> The product of two elements a^b should be give by p[a,b] so I
>> make p flat:
>> 
>> SetAttributes[p, {Flat}]
>> 
>> But now I want p[a] to reduce to a.
>> Such a  rule would make other rules much simpler but when I define
>> 
>> p[a_] := a
>> 
>> the expression p[a] causes an infinite recursion. I get the message
>> 
>> $IterationLimit::itlim: Iteration limit of 4096 exceeded.
>> 
>> I have similar problems with p[]:=1 which makes mathematica puts
>> ones into the p : p[a]=p[a,a]=p[1,1,...,a] .
>> 
>> How can I solve this problem?

SetAttributes[p, {Flat, OneIdentity}]
p[a_] := a
p[] := 1
p[a]
$IterationLimit::itlim :  "Iteration limit of 4096 exceeded. \

[toc] | [prev] | [standalone]

Back to top | Article view | comp.soft-sys.math.mathematica

csiph-web