Re: A little simplification problem

Ralf Hemmecke <[email protected]> Fri, 01 Aug 2008 16:43:04 +0200
Newsgroups gmane.comp.mathematics.axiom.user
Message-ID <[email protected]>
On 08/01/2008 04:18 PM, Alasdair McAndrew wrote:
> f(n)==7^n
> f(n+1)-7*f(n)
> simplify(%)
> 
> What do I need to do to enable the final statement to produce 0?

Does that help?

(1) -> f(n)==7^n
     Type: Void

(2) -> a := f(n+1)-f(n)*7

          n + 1      n
    (2)  7      - 7 7
    Type: Expression Integer

(3) -> r := rule x^(y+1)==x*x^y

          y + 1       y
    (3)  x      == x x
    Type: RewriteRule(Integer,Integer,Expression Integer)

(4) -> r a
    (4)  0
    Type: Expression Integer