formal/lazy/infinite powerseries

[sagetrac-Henryk-Trappmann]

New code that implements lazy power and Laurent series.

CC: @sagetrac-sage-combinat @mantepse

Component: algebra

Keywords: LazyPowerSeries

Author: Henryk Trappmann

Reviewer: Martin Rubey

Issue created by migration from https://trac.sagemath.org/ticket/6800

[sagetrac-Henryk-Trappmann]

Attachment: 12846.patch.gz

patch adds the file formal_powerseries.py

[aghitza]

comment:1

The documentation needs some serious reformatting to adhere to the ReST format. I am cc-ing sage-combinat because a lot of people there would be interested in formal power and Laurent series.

[aghitza]

Author: Henryk Trappmann

[mantepse]

Changed keywords from none to LazyPowerSeries

[rwst]

comment:5

I think although there is combinat.species.series.LazyPowerSeries this implementation would still be good to have, as the implementation in combinat misses many features included here. It is also needed for P-finite sequences.

However, I don't think it's right to define all special functions anew: the ring or a static function should be able to create a series from a symbolic expression (interpreted as e.g.f.), and , in case of a rational polynomial, delegate to CFiniteSequence (#15714).

There were a few failures:

   1 of  39 in sage.rings.formal_powerseries.FormalPowerSeries
   1 of   6 in sage.rings.formal_powerseries.FormalPowerSeries.nipow
   1 of   6 in sage.rings.formal_powerseries.FormalPowerSeries.pow
   3 of   8 in sage.rings.formal_powerseries.FormalPowerSeries0.abel
   1 of   4 in sage.rings.formal_powerseries.decidable0

[mantepse]

comment:8

This is subsumed by #32324.

[mantepse]

Reviewer: Martin Rubey