# [Maxima] finding subterms in a bigger term

andre maute andre.maute at gmx.de
Mon Sep 17 04:50:58 CDT 2007

```Hi Maxima mailinglist,

I'm experimenting with non-classical orthogonal polynomials.

I have set,

gammalim : -2;

because I don't want the gamma function to be evaluated.

I have the constraints
a > -1, a real, and b > -1, b real
but they are not used within my Maxima source at the moment.

I have terms being polynomial in gamma terms like the following

------------------------------------------------------------------------------
(%o13) ((gamma (a + 1) gamma (b + 1) gamma (b + a + 3)
2             2
+ (- gamma (a + 1) gamma (b + 2) + 2 gamma(a + 1) gamma(a + 2) gamma(b + 1)
2             2              2
gamma(b + 2) - gamma (a + 2) gamma (b + 1)) gamma (b + a + 2))
2                    2
gamma (b + a + 4) + (gamma (a + 1) gamma(b + 1) gamma(b + 3)
- 2 gamma(a + 1) gamma(a + 2) gamma(b + 1) gamma(b + 2)
2                               2
+ gamma(a + 1) gamma(a + 3) gamma (b + 1)) gamma(b + a + 2) gamma (b + a + 3)
gamma(b + a + 4)) gamma(b + a + 5)
------------------------------------------------------------------------------

Question:

How can I find minimal n1, n2, n3 such that

gamma(a+n1), gamma(b+n2) and gamma(a+b+n3)

are appearing in the above term?

I want to use gamma(x+1) = x*gamma(x)

Regards
Andre
```