Model (Logic)

logic

Definition

Model

A model is a semantic object under which a formula is true.

In propositional logic, a model is a variable assignment that maps propositional variables to truth values.

In first-order logic, a model is an interpretation together with a variable assignment such that

The formula is true under that interpretation and assignment.

Set of Models

For a formula , the set of its models is

This set is used to compare logical strength and entailment.