Someone has the code of the old macsyma function called TRIGCONTRACT ?
I read an old post to sci.math describing this "experimental"
function of Macsyma.
http://mathforum.org/discuss/sci.math/a/m/68239/68242
Here some excerpts from the above link
Subject: Re: A definite Integral
Author: Jeffrey P. Golden <jpg@math.math.unm.edu>
Date Posted: Aug 5 1996 8:51:01:000PM
Reply-To: jpg@macsyma.com
> Date: Fri, 02 Aug 1996 09:30:37 -0500
> From: G. A. Edgar
> Subject: Re: A definite Integral
(...)
/* Here is the desired integral */
(c1) 'integrate(x/(sin(x)+cos(x)),x,0,%pi/2);
%pi
---
2
/
[ x
(d1) I --------------- dx
] sin(x) + cos(x)
/
0
/* TRIGCONTRACT is a new function in the development version of
Macsyma that transforms a sum of trigonometric functions into a
product of trigonometric functions. It many situations TRIGCONTRACT
is essentially an inverse to the already existing TRIGREDUCE. */
(c2) trigcontract(%);
%pi
---
2
/
[ x
sqrt(2) I ------------ dx
] %pi
/ cos(x - ---)
0 4
(d2) ----------------------------
2