Re: arithmetic expressions simplifier

On Tue, May 13, 2003 at 11:42:49AM +0100, Chris Meudec wrote:
> Hi all,
> I am looking for an arithmetic expressions simplifier. I have been using 
> tidy.pl by O'Keefe distributed with eclipse but it is quite limited in that it 
> only simplies ground terms.
> 
> I need something that simplifies say, A+A+A+1+3*A+2+3-B-B into 6*A 
> + 6-2*B. Basically the output should be in a human readable form.
> 
> Any pointer as to where I might find such a thing?

It's not quite what you want, but you may find the linearize library useful
(see the reference manual for details).

E.g.

[eclipse 1]: lib(linearize).
linearize.eco loaded traceable 0 bytes in 0.08 seconds

Yes (0.08s cpu)
[eclipse 2]: linearize(A+A+A+1+3*A+2+3-B-B, Linear, Nonlinear).

A = A
B = B
Linear = [6 * 1, 6 * A, -2 * B]
Nonlinear = []
Yes (0.00s cpu)
[eclipse 3]: linearize(A+A+A+1+3*A+2+3-B-B, Linear, Nonlinear), delinearize(Linear, Expr).

A = A
B = B
Nonlinear = []
Linear = [6 * 1, 6 * A, -2 * B]
Expr = 6 + 6 * A - 2 * B
Yes (0.00s cpu)
[eclipse 4]: 


If you have nonlinear bits in your expressions, you need to do some more
work...

Cheers,
Warwick