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Logical quantifiers
From OeisWiki
Logical quantifiers are used in first order logic and in logic of higher order.
Existential quantifier
The existential quantifier, i.e. there exists at least one, is denoted with the inverted latin character .
Uniqueness quantifier
The uniqueness quantifier, i.e. there exists one and only one, is denoted with .
Example:
Universal quantifier
The universal quantifier, i.e. for all, is denoted with the inverted latin character .