Editing Falling and rising factorials (section)

==Alternative notations==
An alternative notation for the rising factorial
<math display="block">
x^\overline{m} \equiv (x)_{+m} \equiv (x)_m = \overbrace{x(x+1)\ldots(x+m-1)}^{m \text{ factors}} \quad \text{for integer } m\ge0 </math>

and for the falling factorial
<math display="block">
x^\underline{m} \equiv (x)_{-m} = \overbrace{x(x-1)\ldots(x-m+1)}^{m \text{ factors}} \quad \text{for integer } m \ge 0</math>

goes back to A. Capelli (1893) and L. Toscano (1939), respectively.<ref name="The Art of Computer Programming"/> Graham, Knuth, and Patashnik<ref name=Graham-Knuth-Patashnik-1988/>{{rp|style=ama|pp= 47, 48}}
propose to pronounce these expressions as "<math>x</math> to the <math>m</math> rising" and "<math>x</math> to the <math>m</math> falling", respectively.

An alternative notation for the rising factorial <math>x^{(n)}</math> is the less common <math>(x)_n^+</math>. When <math>(x)_n^+</math> is used to denote the rising factorial, the notation <math>(x)_n^-</math> is typically used for the ordinary falling factorial, to avoid confusion.<ref name="Knuth" />