The two most common quantifiers are the universal quantifier and the existential quantifier. Theories could be decidable yet not admit quantifier elimination. Variables not bound by an existential quantifier are bound by an implicit universal quantifier. The negation of one quantifier is the other quantifier (formula 47 and formula 48). There are several rules of inference which utilize the existential quantifier. The equivalence provides a way for "moving" an existential quantifier before a universal one. Pinker prefers the terms "quantifier" and "bound variable" to "antecedent" and " pronoun". The let expression is a conjunction within an existential quantifier. Here we see an objective complement of a finite verb begin with the quantifier. There are several rules of inference which utilize the universal quantifier. A formula beginning with a quantifier is called a quantified formula. I to a quantifier free theory of functionals F. The following example shows this morpheme as an 'only' quantifier. Moreover, there is but one existential quantifier, in axiom 3. One technical term for such words is "non-numerical vague quantifier".