Re: [Axiom-developer] Issue 336

[Martin Rubey]

Waldek Hebisch <address@hidden> writes:

> The fix for bug 336 looks fine.  But one thing in original
> code looks strange: we are testing if s>0.  s belongs to some
> ring which  has RetractableTo(Z) and we test that if s can
> be retracted to Z.  Then use s in comparizon.  AFAIU the 
> comparison is taken from R and in principle can be quite
> different than comparison in Z.  However, the logic really
> requires comparison in Z.  So I think that we should 
> use here t (that is value retracted to Z) in comparison.

Yes, we are actually interested whether first l or first l - second l are a
positive integer, i.e., we should use t there.

If the second argument k is negative, we could return zero. However, I vaguely
remember that the definition in terms of Gamma functions does not yield this as
a limit, at least not for any n. Do you happen to remember?

In fact, if n=k, the definition in terms of Gamma functions always gives one,
no matter whether n is negative of not...

Axiom gives 0 currently, due to the definition of ibinom. This looks all quite
inconsistent...

Martin