From: C Y
Subject: Qi vs. SPAD/Aldor?
Date: 
Message-ID: <1190123436.889301.293900@k79g2000hse.googlegroups.com>
I've seen a few posts over time about the new Qi language being
implemented in Lisp, and I'm curious because some of the discussions
pop up with keywords similar to what I've seen in the past with
Axiom.  "Strongly typed" certainly is one, and the discussion of Unit
types last month also caught my interest.  I'm curious if anybody who
knows could compare the Aldor.org language to Qi?  What are their
differences?  (SPAD if you prefer to do an apples-to-apples "language
implemented in Lisp" comparison.)  Would Qi be as suitable for
advanced mathematical programming as Aldor (given some library
support, presumably...)
From: Mark Tarver
Subject: Re: Qi vs. SPAD/Aldor?
Date: 
Message-ID: <1190637441.975629.151700@22g2000hsm.googlegroups.com>
On 18 Sep, 14:50, C Y <···········@yahoo.com> wrote:
> I've seen a few posts over time about the new Qi language being
> implemented in Lisp, and I'm curious because some of the discussions
> pop up with keywords similar to what I've seen in the past with
> Axiom.  "Strongly typed" certainly is one, and the discussion of Unit
> types last month also caught my interest.  I'm curious if anybody who
> knows could compare the Aldor.org language to Qi?  What are their
> differences?  (SPAD if you prefer to do an apples-to-apples "language
> implemented in Lisp" comparison.)  Would Qi be as suitable for
> advanced mathematical programming as Aldor (given some library
> support, presumably...)

I'm back from travelling and caught this.

I've not used Axiom or SPAD.

Re: mathematical programming; the Qi philosophy is the antithesis of
PL/1's - a small number of primitives and a powerful means of
extending and adapting the language.

Hence Qi has a fairly small set of typed math'l functions but makes it
easy to add functions to its type theory.
http://www.lambdassociates.org/webbook/appendixB.htm
shows you how to do this for any Lisp system function such
as TAN or COS.

Once you've got this far you can then move to providing type theories
for Lisp math'l packages like Lispstat; there is really no difference
there.

More advanced techniques rely on axiomatising the portion of
mathematics you are interested in. For examples

Study 1 on the type theory of interval arithmetic
http://www.lambdassociates.org/studies/study01.htm

Study 11 on the type theory of metrics
http://www.lambdassociates.org/studies/study11.htm

also entropyfails studies

Qi and the Magic Prime Type
http://programmingkungfuqi.blogspot.com/2006/04/qi-and-magic-prime-type.html

Formalising Peano's Axioms in Qi
http://groups.google.co.uk/group/Qilang/topics?hl=en&start=30&sa=N

entropyfails is active on Qilang and there are 60 members on that
group if you want advice and support.

Mark