Symbolic limit

[rwst]

Equivalently to #21645 a symbolic limit function is needed, in this case #20179 supposes that expressions can be searched for unexpanded limit functions which is not possible if it is anonymous.

CC: @EmmanuelCharpentier

Component: symbolics

Author: Ralf Stephan

Branch/Commit: ce95d01

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/22844

[rwst]

Branch: u/rws/symbolic_limit

[rwst]

Commit: 2f5a28f

[rwst]

Author: Ralf Stephan

[sagetrac-git]

Changed commit from 2f5a28f to bd403fd

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

bd403fd

22844:internal symbolic limit function

[rwst]

comment:5

Doctest failures in src/sage/calculus/calculus.py.

[rwst]

comment:6

The latex conversion would be easily fixed. However, the fails show that there is the problem that the limit function can have either 3 or 4 arguments, the latter with an additional direction. I don't think Sage can handle this at the moment without tuples as arguments like in hypergeometric, and this would change the code substantially.

EDIT: it may be possible to use two functions; checks elsewhere would then have to be done with both. The Maxima interface would have to know about it.

[rwst]

comment:7

Maybe it is excusable in this case to write a customized __call__ member, as long as it's an internally only used function.