feat(ring_theory/polynomial): Pochhammer polynomials (#6598)
feat(ring_theory/polynomial): Pochhammer polynomials (#6598)

# The Pochhammer polynomials

We define and prove some basic relations about
`pochhammer S n : polynomial S = X * (X+1) * ... * (X + n - 1)`
which is also known as the rising factorial.



Co-authored-by: Scott Morrison <63f04b4d96235eb042cc46d94f14d241d2a26722@gmail.com>

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