Trac #15737: Error relating to precision in sha_tate
Trac 15737: adjusting the ordinary case
Trac 15737: fixing the supersingular case, too
DiGraph.is_aperiodic: new method (wraps networkx method)
DiGraph.is_aperiodic: Add Wikipedia link to docstring
Trac 15737: small correction
Trac #16062: DiGraph.is_aperiodic: new method (wraps networkx method)

This simply wraps the networkx method of the same method, but wrapping
it may help to find the function in the sage documentation. Furthermore,
other code calling DiGraph.is_aperiodic would
benefit from eventual other implementations for other backends.

URL: http://trac.sagemath.org/16062
Reported by: cheuberg
Ticket author(s): Clemens Heuberger
Reviewer(s): Nathann Cohen
Trac #15737: Problem in an_padic

The following produces a error

{{{
E = EllipticCurve([-100,0])
s = E.sha()
s.an_padic(13)
}}}

The error comes from the an_padic asking for only the first constant
coefficient of the p-adic L-series. But it does not harm to compute the
next one too. (This arises only when a twist is involved, otherwise the
the modular symbol at 0 is called directly.)

URL: http://trac.sagemath.org/15737
Reported by: wuthrich
Ticket author(s): Chris Wuthrich
Reviewer(s): Peter Bruin