RE: [Axiom-developer] RE: symbolic manipulation of expressions in Axiom

[Bill Page]

On April 1, 2007 3:31 PM Gaby wrote:
> ...
> I regret to say, but I'm a big fan of encapsulation (where useful)
> and prefer to see interfaces even if I'm spending all my time
> tweaking in the innards.  Thanks for the illustation. 
> 

No problem.

> The difference, as I see it comes from the larger number of
> supported mathematical operations for Expression T, than there
> are for InputForm.

There are *no* mathematical (algebraic) operations in InputForm!
That is the whole point of the discussion.

> Augment InputForm with all useful mathematical operations
> working on InputForm and you'll see very little difference
> from Expression T.

That is completely wrong. There is still a huge difference
as I have now explained at least two different ways. :-(
The operations in InputForm are purely symbolic. They could
be written in simple Lisp or Python just as easily. That is
definitely not true of Expression. Expression requires a very
large portion of Axiom's library.

> Hence, Martin's warning.

I do not understand Martin's warning. I think it under the
wrong impression (just as you are) about what I am saying.

> 
> Also, be aware than the Axiom designers, in many places,
> thought of Expression as the general domain for symbolic
> manipulation and have appropriate hardwired type inference
> rules in the interpreter.
> 

Of course that is no problem. If you are able to read and
understand Stephen Watt's paper on this subject, I am sure
that this would be clear to you.

Regards,
Bill Page.