Hi Ian -

Ken Iverson's Concrete Math Companion,
http://www.jsoftware.com/books/pdf/cmc.pdf,  has 2 pages dedicated to
it starting on page 59. I am too rusty on this level of math to
comment on how well it describes it. It makes some sense and seems
pretty clear.

GKP5.76 defines the hypergeometric as a sum over the products of two
lists for all k not
less than zero. The first list is the quotient of products over the
rising factorials of two list
parameters denoted by a and b, and the second is the powers of the
argument z divided
by corresponding factorials.

To confine the matter to finite lists, we will introduce a further
argument t, and treat only
the values of k specified by i. t. The definitions will be used in the
form t a hy b z,
where hy is a conjunction. Thus:

The primitive hypergeometric conjunction H. produces a rank-0 dyadic function
equivalent to a hy b, and a monadic case that is its limit for an
unlimited number of
terms. For example:


I particularly like how the CMC shows tests cases between the full
definition and H.

 (10) 1 hy 1 " 0 i. 6
1 2.71828 7.38871 20.0634 54.1541 143.689

 10 '' H. '' i. 6
1 2.71828 7.38871 20.0634 54.1541 143.689

Between wikipedia[1] and the Concrete Math Companion, I could probably
figure it out, but not this early on a Saturday without coffee yet.

Hope it helps in some way or perhaps triggers thoughts for others to contribute

[1] - http://en.wikipedia.org/wiki/Hypergeometric_function

On Sat, Jan 18, 2014 at 6:01 AM, Ian Clark <[email protected]> wrote:
> Just one empty stub remains in the Accessible Dictionary (aka NuVoc
> --remember it?):
>
> H. (Hypergeometric) Conjunction
> http://www.jsoftware.com/jwiki/Vocabulary/hcapdot
>
> Once that's filled-in, then NuVoc is more-or-less ready to go. You can
> already see it at http://www.jsoftware.com/jwiki/Vocabulary
> But alas, I need help...
>
> The J Dictionary (the old one) references Abramowitz and Stegun (A&S),
> Chapter 15: Hypergeometric Functions. Now A&S represent the syntax of the
> general case like so:
>
>    F(a; b; c; z)
>
> Both NuVoc and the J Dictionary present the syntax of the (H.) primitive
> like so:
>
>    (m H. n) y
>
> where both m and n are numeric lists.
>
> Now suppose I'm a newbie, and my first sight of:
>  http://www.jsoftware.com/help/dictionary/dhcapdot.htm
> just gives me a dull ache between the eyes. I need clear, unambiguous
> instructions for taking any example I choose from A&S and mapping it onto:
> (m H. n)y
>
> Let me make a start:
>     z --> y
> That was the easy bit. Now... how should (a; b; c) --> (m; n)?
>
> Or should I be asking: how *best* should (a; b; c) be mapped onto m and n?
> Because as I see it, it's ambiguous. Just for starters:
>
>    F(a; b; c; z) = F(b; a; c; z)   -----[A&S 15.1.1]
>
> Suggestions please.
>
> IanClark
> ----------------------------------------------------------------------
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