- published: 12 Jun 2016
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In predicate logic, universal quantification formalizes the notion that something (a logical predicate) is true for everything, or every relevant thing. The resulting statement is a universally quantified statement, and we have universally quantified over the predicate. In symbolic logic, the universal quantifier (typically Failed to parse (Missing texvc executable; please see math/README to configure.): \forall , U+2200 ∀ , a turned A) is the symbol used to denote universal quantification, and is often informally read as "given any" or "for all". Universal quantification is distinct from existential quantification ("there exists"), which asserts that the property or relation holds for at least one member of the domain.
Quantification in general is covered in the article on quantification. Symbols are encoded U+2200 ∀ for all (HTML: ∀
∀
as a mathematical symbol).
Suppose it is given that
2·0 = 0 + 0, and 2·1 = 1 + 1, and 2·2 = 2 + 2, etc.
This would seem to be a logical conjunction because of the repeated use of "and." However, the "etc." cannot be interpreted as a conjunction in formal logic. Instead, the statement must be rephrased: