[Maxima] finding subterms in a bigger term
macrakis at alum.mit.edu
Tue Sep 18 12:53:40 CDT 2007
On 9/18/07, Richard Fateman <fateman at cs.berkeley.edu> wrote:
> As it happens, this is done by factcomb(). Try it.
Factcomb gives surprising (though correct) results in many cases. Sometimes
a judicious combination of minfactorial and factcomb gives simple-looking
results, sometimes not. Of course, what is "simple" is in the user's eye.
factcomb((x+1)!/x!) => (x+1)!/x!
(I would have expected x+1, which you can get with minfactorial)
factcomb( x^2 * (x-1)! ) => (x+1)! - x!
(I would have expected x*x!;
minfactorial of input leaves it unchanged;
of output gets (x+1)*x!-x! )
factcomb( x!/x^2 ) => (x-2)! * (x-1)! / ((x-1)! + (x-2)!)
(I would have expected (x-1)!/x , which no combination of
minfactorial and factcomb gets)
This may be some well-defined quasi-canonical form, for all I know.
In Andre's case, it blows up the expression quite a bit, apparently not in a
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Maxima