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Re: subscripts in v3

  • To: mathgroup at
  • Subject: [mg6645] Re: [mg6594] subscripts in v3
  • From: seanross at
  • Date: Wed, 9 Apr 1997 00:34:07 -0400 (EDT)
  • Sender: owner-wri-mathgroup at

Robert wrote:
> Since Wolfram are represented on this forum I thought it would be worth
> canvasing other users on how they feel about the way subscripts work in v3. It
> may be that as an Engineer I'm expecting the subscripts to be 'dead' when in
> fact others are looking for them to be 'live'. I can see that mathematicians
> might want them to be live (tensors perhaps?!), however, from a purely
> presentational point of view it would be nice to have a symbol, say sigma.sub.x,
> in which the x remains purely part of the symbol and is not substituted when x
> is evaluated elsewhere.
> I guess the first question is am I being daft by having misinterpreted what
> should be the primary intent - and if not do we want v3 .1 or v4 to be more like
> a textbook representation of the maths.

   My feeling is that subscripts should be "dead" or "alive" depending 
on what kind of object they are attached to and should never be used by 
mathematica to determine object type.  If the non subscripted symbol is 
anything but a list, the subscript should be dead.  If the non 
subscripted symbol is a list, then it should be live.  Better yet, make 
some convention like [[ in the subscript to indicate live subscripts and 
make them dead otherwise.
   Since we are on the subject of opinions, mathematica needs to include 
the ability to have formal type declaration statements like other 
computer languages.  I don't mind having mathematica decide the variable 
type from the context, but sometimes I would like to have the ability to 
override the default.  The whole subscript thing could be solved by 
including this ability.  Then, a person who wanted a "dead" subscript 
could simply include a line like:


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