Elementary Symmetric Function/Examples/m = 0

From ProofWiki
Jump to navigation Jump to search

Example of Elementary Symmetric Function: $m = 0$

Let $\map {e_0} {\set {x_1, x_2, \ldots, x_n} }$ be an elementary symmetric function in $n$ variables of degree $0$.


Then:

$\map {e_0} {\set {x_1, x_2, \ldots, x_n} } = 1$


Proof

By definition:

\(\ds \map {e_0} {\set {x_1, x_2, \ldots, x_n} }\) \(=\) \(\ds \sum_{1 \mathop \le n} \paren {\prod_{i \mathop = 1}^0 x_{j_i} }\)
\(\ds \) \(=\) \(\ds \sum_{1 \mathop \le n} \paren 1\) Definition of Vacuous Product
\(\ds \) \(=\) \(\ds 1\)



Whether the summation $\ds \sum_{1 \mathop \le n}$ makes sense, as such, is a moot point.

$\blacksquare$