# [Maxima] Seems like a bug in integrate

Richard Hennessy rich.hennessy at verizon.net
Sun May 24 12:34:40 CDT 2009

```Someone pointed out correctly I think that the unqualified "best" answer to input 2 should be

(%i2) integrate(1/(x^2+1)*exp(-2*%i*%pi*x*t),x,minf,inf);
(%o2) %pi*%e^(- 2*%pi*abs(t))

This is a difficulty in Maxima since it was created without an ability to render output in piecewise fashion.  Abs(t) is a piecewise
function that can be written pw([minf,-t,0,t,inf],x), maybe this is taking on too much but I wonder if noninteractive.mac could be
modified to output the unqualified correct answer using the pw function or in this case the abs function?

Rich

----- Original Message -----
From: "Robert Dodier" <robert.dodier at gmail.com>
To: "Richard Hennessy" <rich.hennessy at verizon.net>
Cc: "Dieter Kaiser" <drdieterkaiser at web.de>; <maxima at math.utexas.edu>
Sent: Sunday, May 24, 2009 1:21 AM
Subject: Re: [Maxima] Seems like a bug in integrate

On 5/22/09, Richard Hennessy <rich.hennessy at verizon.net> wrote:

> (%i1) integrate(1/(x^2+1)*exp(-%i*%pi*x*t),x,minf,inf);
> Is  t  positive, negative, or zero?
> p;
> (%o1) %pi*%e^(-%pi*t)
> (%i2) integrate(1/(x^2+1)*exp(-2*%i*%pi*x*t),x,minf,inf);
> Is  t  positive, negative, or zero?
> p;
> (%o2) %pi*%e^(- 2*%pi*t)
> (%i3) integrate(%*exp(2*%i*%pi*x*t),t,minf,inf);
> Maxima encountered a Lisp error:
>  Unhandled kernel in tvar-lim

I see the same error with Maxima built from CVS.
Can you make a bug report about it? Thanks for your help.

Robert Dodier

```