<logic> 1. In predicate logic, to remove a quantifier from a wff and either leave the previously bound variables free or replace them with constants. See generalization, quantifier
Existential instantiation
Instantiation from the existential quantifier. For example, to move from statements like (Ex)Px to Px or Pa; from "something is purple" to "x is purple" or "alabaster is purple". Valid only under several restrictions.
Universal instantiation
Instantiation from the existential quantifier. For example, to move from statements like (x)Px to Px or Pa; from "everything is purple" to "x is purple" or "alabaster is purple". Valid without restriction.
[Glossary of First-Order Logic]
<programming> 2. Producing a more defined version of some object by replacing variables with values (or other variables).
3. In object-oriented programming, producing a particular object from its class template. This involves allocation of a structure with the types specified by the template, and initialisation of instance variables with either default values or those provided by the class's constructor function.
4. In unification, (as used in logic programming, type checking and type inference), binding a logic variable (type variable) to some value (type).
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