MathGroup Archive 2003

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

Search the Archive

Re: Prefix[f[x]], why is it not working

  • To: mathgroup at smc.vnet.net
  • Subject: [mg38941] Re: Prefix[f[x]], why is it not working
  • From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
  • Date: Tue, 21 Jan 2003 07:38:28 -0500 (EST)
  • Organization: Universitaet Leipzig
  • References: <b0app5$dl8$1@smc.vnet.net>
  • Reply-to: kuska at informatik.uni-leipzig.de
  • Sender: owner-wri-mathgroup at wolfram.com

Hi, 

because

Prefix[] *print* the function f[expr] in the form f @ expr.
And printing an expression is quite the 
oposite of parsing/reading a expression.

Regards
  Jens

Ashraf El Ansary wrote:
> 
> Hi all,
> Does anyone why f@a_=2 a gives a proper answer for f[1]
> and not in the case of Prefix[s[a_]]= 2 a eventhough that Prefix[s[a_]]=
> f@a_???
> 
> Thanks
> In[1]:=
> f@a_=2 a
> f[1]
> Out[1]=
> 2 a
> Out[2]=
> 2
> In[3]:=
> Prefix[s[a_]]
> Prefix[s[a_]]=2 a
> s[1]
> Out[3]=
> s@a_
> Set::write: Tag Prefix in s@a_ is Protected.
> Out[4]=
> 2 a
> Out[5]=
> s[1]


  • Prev by Date: Re: Non-mathematician ... please help: Spherical Harmonic Coefficients
  • Next by Date: Problem with Limits; basic calculus
  • Previous by thread: RE: Prefix[f[x]], why is it not working
  • Next by thread: OO System for Mathematica