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Re: Re: Re: Subscripts, Doh!!!

  • To: mathgroup at smc.vnet.net
  • Subject: [mg19320] Re: [mg19296] Re: [mg19269] Re: Subscripts, Doh!!!
  • From: "Carl K.Woll" <carlw at fermi.phys.washington.edu>
  • Date: Sat, 14 Aug 1999 23:42:50 -0400
  • Organization: Department of Physics
  • References: <7o5ier$rme@smc.vnet.net> <7oba5o$3p6@smc.vnet.net> <"199908060358.XAA08108"@smc.vnet.net> <v04210100b3d0c0366e0b@[172.16.41.9]> <"199908120524.BAA04506"@smc.vnet.net> <"199908130234.WAA07302"@smc.vnet.net> <v04210100b3db06a519b8@[172.16.41.9]>
  • Sender: owner-wri-mathgroup at wolfram.com

Jason,

I suppose I should have mentioned why I don't like to use the Symbolize
function. Primarily, it's because I hate to use palettes, and the latest update
of the Notation package required you to use palettes in order to permform a
symbolization. Apparently this has been fixed in version 4.

Jason wrote:

> Moreover, setting attributes on a system level function as major as
> Subscript is begging for trouble. Some packages will break because
> you assume Subscript has the attribute HoldFirst. ( E.g. consider the
> construction of a matrix of coordinates
> Table[Subscript[coord[i],j],{i,1,3},{j,1,3}]].)

This example seems rather contrived to me. Yes, Subscript is a major system
level function. However, it does not have any built in definitions, so it seems
to me that any definitions which will be attached to Subscript will be user
defined. I agree with Colin Rose, a HoldFirst attribute for Subscript is a
better default choice. Then, if you really want to do something unusual, like
your table, you can just stick in an Evaluate in the appropriate place.

> In a similar vein,
> packages that use OverHat would also break, if the attributes of
> OverHat are set to HoldFirst. For instance, if OverHat was used as
> complex conjugation.
>

I agree with you here, OverHat should not by default have any Hold type
attributes. On the other hand, if OverHat will be used just for appearance
reasons, then a Hold attribute seems perfectly reasonable.

Carl Woll
Dept of Physics
U of Washington



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