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===Set===
The ''set'' (or ''powerset'') ''construction'', denoted by <math>\mathcal{A} = \mathfrak{P}\{\mathcal{B}\}</math> is defined as
:<math>\mathfrak{P}\{\mathcal{B}\} = \prod_{\beta \in \mathcal{B}}(\mathcal{E} + \{\beta\}),</math>
which leads to the relation
:<math>\begin{align}A(z) &{} = \prod_{\beta \in \mathcal{B}}(1 + z^{|\beta|}) \\
&{} = \prod_{n=1}^{\infty}(1 + z^{n})^{B_{n}} \\
Line 50 ⟶ 53:
&{} = \exp \left ( \sum_{n = 1}^{\infty} B_{n} \cdot \sum_{k = 1}^{\infty} \frac{(-1)^{k-1}z^{nk}}{k} \right ) \\
&{} = \exp \left ( \sum_{k = 1}^{\infty} \frac{(-1)^{k-1}}{k} \cdot \sum_{n = 1}^{\infty}B_{n}z^{nk} \right ) \\
&{} = \exp \left ( \sum_{k = 1}^{\infty} \frac{(-1)^{k-1} B(z^{k})}{k} \right
\end{align}</math>
where the expansion
:<math>\ln(1 + u) = \sum_{k = 1}^{\infty} \frac{(-1)^{k-1}u^{k}}{k} </math>
was used to go from line 4 to line 5.
===Multiset===
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