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#270 integrating UTS ←	↑	→ #272 functions +-> and blocks of instructions

#271 )show Expression Boolean gives a list

Edit detail for #271 )show Expression Boolean gives a list revision 1 of 7

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Editor: Time: 2007/11/17 22:19:14 GMT-8
Note: [#271 )show Expression Boolean gives a list] cannot reproduce axiom process died

changed:
-
As I was looking for boolean simplification, I type )sh Expression Boolean.
I get the list of the real expressions. So I type 

\begin{axiom}
sin (A::Expression Boolean) or true.
\end{axiom}

Axiom disapproves

>> System error:
Caught fatal error [memory may be damaged]...

And the axiom process died the command-line after.



From BillPage Mon Feb 27 12:37:15 -0600 2006
From: Bill Page
Date: Mon, 27 Feb 2006 12:37:15 -0600
Subject: cannot reproduce axiom process died
Message-ID: <20060227123715-0600@wiki.axiom-developer.org>

I can not reproduce your observation that:

> the axiom process died the command-line after.

This does not happen for me on at least the Windows version of
Axiom.

But I do find it very odd that Axiom allows the construction of
the domain 'Expression Boolean' without complaint:
\begin{axiom}
x:Expression Boolean:=true
\end{axiom}

The scary sounding message: 'Caught fatal error [memory may be damaged]'
occurs for many operations applied to this object.

The definition of the constructor 'Expression R: OrderedSet' seems
wrong to me since there are may operations exported by 'Expression'
that are not naturally interpreted over a domain that is just an
OrderedSet. For example 'Boolean' is considered ordered as follows:
\begin{axiom}
Boolean has OrderedSet
true > false
\end{axiom}

although we might also question the wisdom of considering 'Boolean'
ordered in this way.

From root Fri Mar 3 10:02:57 -0600 2006
From: root
Date: Fri, 03 Mar 2006 10:02:57 -0600
Subject: [#271 )show Expression Boolean gives a list]	cannot reproduce axiom
	process died
Message-ID: <200603031650.k23Gog313599@localhost.localdomain>
In-Reply-To: <20060227123715-0600@wiki.axiom-developer.org>
	(mathaction@axiom-developer.org)

I've been running thousands of integrals thru axiom recently.
There is a problem related to interrupting Axiom while garbage
collection is running (I'm guessing) and, very occasionally,
Axiom will generate an error or die completely (only once so far).
However if Axiom is not interrupted I have yet to see it fail.

The "memory may be damaged" message occurs quite often but I have
yet to see any surface damage on the DIMM packages :-). I'm not
sure why Bill thought this was a reasonable error message but it
does not seem to be a problem. Only console interrupts have caused
failure so far and those seem to be related to some race condition
in garbage collection.

Tim

As I was looking for boolean simplification, I type )sh Expression Boolean. I get the list of the real expressions. So I type

axiomsin (A::Expression Boolean) or true.
  Line   1: sin (A::Expression Boolean) or true.
           ...................................A
  Error  A: syntax error at top level
  Error  A: Improper syntax.
   2 error(s) parsing

Axiom disapproves

>> System error: Caught fatal error [memory may be damaged]?...

And the axiom process died the command-line after.

cannot reproduce axiom process died --Bill Page, Mon, 27 Feb 2006 12:37:15 -0600 reply

I can not reproduce your observation that:

the axiom process died the command-line after.

This does not happen for me on at least the Windows version of Axiom.

But I do find it very odd that Axiom allows the construction of the domain Expression Boolean without complaint:

axiom
x:Expression Boolean:=true

(1)

Type: Expression Boolean

The scary sounding message: 'Caught fatal error [memory may be damaged]?' occurs for many operations applied to this object.

The definition of the constructor Expression R: OrderedSet seems wrong to me since there are may operations exported by Expression that are not naturally interpreted over a domain that is just an OrderedSet?. For example Boolean is considered ordered as follows:

axiom
Boolean has OrderedSet

(2)

Type: Boolean

axiom
true > false

(3)

Type: Boolean

although we might also question the wisdom of considering Boolean ordered in this way.

[#271 )show Expression Boolean gives a list]? cannot reproduce axiom process died --root, Fri, 03 Mar 2006 10:02:57 -0600 reply

I've been running thousands of integrals thru axiom recently. There is a problem related to interrupting Axiom while garbage collection is running (I'm guessing) and, very occasionally, Axiom will generate an error or die completely (only once so far). However if Axiom is not interrupted I have yet to see it fail.

The "memory may be damaged" message occurs quite often but I have yet to see any surface damage on the DIMM packages :-). I'm not sure why Bill thought this was a reasonable error message but it does not seem to be a problem. Only console interrupts have caused failure so far and those seem to be related to some race condition in garbage collection.

Tim