Category:Bonferroni Inequalities

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This category contains pages concerning Bonferroni Inequalities:


The Bonferroni inequalities are a generalization of Boole's Inequality:


Let $E = \set {E_1, E_2, \ldots, E_n}$ be a set of $n$ events.

Let $\overline E = \set {\overline {E_1}, \overline {E_2}, \ldots, \overline {E_n} }$ be the set of complementary events to each of $\set {E_1, E_2, \ldots, E_n}$ respectively.

Let:

\(\ds S_0\) \(:=\) \(\ds 1\)
\(\ds S_1\) \(:=\) \(\ds \sum_{1 \mathop = 1}^n \map \Pr {E_i}\)
\(\ds S_2\) \(:=\) \(\ds \sum_{1 \mathop \le i \mathop < j \mathop \le n} \map \Pr {E_i \cap E_j}\)
\(\ds \) \(\cdots\) \(\ds \)
\(\ds S_k\) \(:=\) \(\ds \sum_{1 \mathop \le i_1 \mathop < \cdots \mathop < i_k \mathop \le n} \map \Pr {E_{i_1} \cap E_{i_2} \cap \cdots \cap E_{i_k} }\)
\(\ds \) \(\cdots\) \(\ds \)
\(\ds S_n\) \(:=\) \(\ds \map \Pr {\bigcap E}\)

where:

$\map \Pr {E_i}$ denotes the probability of $E_i$
$\bigcap E$ denotes the intersection of $E$.


When $n$ is odd:

\(\ds \map \Pr {\bigcup_{i \mathop = 1}^n E_i}\) \(=\) \(\ds \sum_{j \mathop = 1}^n \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\le\) \(\ds \sum_{j \mathop = 1}^{n - 2} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\le\) \(\ds \sum_{j \mathop = 1}^{n - 4} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\le\) \(\ds \cdots\)
\(\ds \) \(\le\) \(\ds \sum_{j \mathop = 1}^1 \paren {-1}^{j - 1} S_j\)

and:

\(\ds \map \Pr {\bigcup_{i \mathop = 1}^n E_i}\) \(=\) \(\ds \sum_{j \mathop = 1}^n \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\ge\) \(\ds \sum_{j \mathop = 1}^{n - 1} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\ge\) \(\ds \sum_{j \mathop = 1}^{n - 3} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\ge\) \(\ds \cdots\)
\(\ds \) \(\ge\) \(\ds \sum_{j \mathop = 1}^2 \paren {-1}^{j - 1} S_j\)


When $n$ is even:

\(\ds \map \Pr {\bigcup_{i \mathop = 1}^n E_i}\) \(=\) \(\ds \sum_{j \mathop = 1}^n \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\le\) \(\ds \sum_{j \mathop = 1}^{n - 1} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\le\) \(\ds \sum_{j \mathop = 1}^{n - 3} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\le\) \(\ds \cdots\)
\(\ds \) \(\le\) \(\ds \sum_{j \mathop = 1}^1 \paren {-1}^{j - 1} S_j\)

and:

\(\ds \map \Pr {\bigcup_{i \mathop = 1}^n E_i}\) \(=\) \(\ds \sum_{j \mathop = 1}^n \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\ge\) \(\ds \sum_{j \mathop = 1}^{n - 2} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\ge\) \(\ds \sum_{j \mathop = 1}^{n - 4} \paren {-1}^{j - 1} S_j\)
\(\ds \) \(\ge\) \(\ds \cdots\)
\(\ds \) \(\ge\) \(\ds \sum_{j \mathop = 1}^2 \paren {-1}^{j - 1} S_j\)


In particular:

$\map \Pr {\bigcap E} > 1 - \ds \sum_{i \mathop = 1}^n \map \Pr {\overline E_i}$

which is a statement of Boole's Inequality.

Pages in category "Bonferroni Inequalities"

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