Go backward to Equality Go up to Top Go forward to Universal Quantification

Quantified Formulas

Definition: Quantifier

• A syntactic operator that combines a variable and a phrase to form a new phrase.
• The meaning of the new phrase does not depend on the value of the variable in the given assignment.
• We call this variable bound by the quantifier.
• If all variables in a phrase are bound, the phrase is called closed.

Example: Formula x < 1.

• x is free (not bound) in this formula.