```Date: Jul 16, 2013 4:05 AM
Author: daly@axiom-developer.org
Subject: Re: An independent integration test suite

On Tuesday, July 16, 2013 4:00:13 AM UTC-4, da...@axiom-developer.org wrote:> On Tuesday, July 16, 2013 2:19:26 AM UTC-4, Albert Rich wrote:> > > On Monday, July 15, 2013 9:36:04 AM UTC-10, da...@axiom-developer.org wrote:> > > > > > > > > > > > > In order to ensure that the answers of the integration differ by no> > > > > > > more than a constant I've been differencing the expected answer from> > > > > > > the Axiom answer and then taking the derivative.> > > > > > > > > > > > > > One curious pattern is that your answers differ from Axiom's answers> > > > > > > by non-zero constants. [...]> > > > > > > > > > > > The first sentence above correctly asserts that it is ok for antiderivatives to differ by a constant.  Yet, the second sentence finds it surprising that they do differ.  So what is the problem?> > > > > > > > > > > > Albert> > > > suppose> > t0:= expression> > r0:= expected result> > a0:= integrate(t0,x)> > m0:= a0 - r0> > d0:= differentiate(m0,x)> > > > m0 is the difference between Axiom's result and the expected result.> > d0 is the derivative of m0, usually with a value of 0.> > > > m0 often shows that Axiom's result and the expected result differ > > and the derivative result of 0 shows that this is just a constant.> > > > When I look at the reason for the constant difference it seems to be> > related to the trig identities we chose. What system did you use to> > create the expected results?That last was just a dumb question... you used Rubi, no doubt.What I wanted to ask was what trig substitutions you use.Is there somewhere in the Rubi sources I should look?
```