A quantifier, denoted

\[\begin{align*} \exists! x \>\> P(x), \\ \exists_{= 1} x \>\> P(x), \end{align*} \]

and read

“there exists exactly one *\(x\)* such that *\(P(x)\)*”

which is equivalent to

\[\begin{equation*} \forall x \exits y : P(x) \iff x = y \end{equation*} \]

where *\(P\)* is the *quantified* predicate.

© 2024 Rudolf Adamkovič under GNU General Public License version 3.

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