Well, Maple didn't invent this mess. Given.
But Maple has done nothing in the last 30 years to mitigate
this mess for its users.
It would be so easy to introduce two functions, 'FallingFactorial'
and 'RisingFactorial', which make it clear to everyone from
the outset what they are using, without first looking
it up in the Maple help or even stumbling into an incorrect
Ok, so this is an official feature request, 24 years after
the release of Graham&Knuth&Patashink, 'Concrete Mathematics':
To add these two functions to the official canon of Maple Functions.
But to save the reader of these lines from having to look it up:
In Maple the Pochhammer Symbol is the same as the rising factorial.
And is displayed in the Jupyter Notebook as (x)_n (in Tex notation).
And this adds to further confusion! Because that is the representation
of the falling factorial, as can be seen on Wikipedia and Mathworld.
Please take the request seriously. Help your users by adapting to the
general development in the community. It's bad enough having to deal
with a user interface reminiscent of the mid-1990s.