Second-Order Predicate Logic
This quiz covers the concepts of Second-Order Predicate Logic, a branch of mathematical logic that extends first-order predicate logic by allowing quantification over predicates.
Questions
In second-order predicate logic, what is the difference between a first-order predicate and a second-order predicate?
- A first-order predicate is a property of individuals, while a second-order predicate is a property of properties.
- A first-order predicate is a relation between individuals, while a second-order predicate is a relation between properties.
- A first-order predicate is a function from individuals to truth values, while a second-order predicate is a function from properties to truth values.
- A first-order predicate is a set of individuals, while a second-order predicate is a set of properties.
Which of the following is a valid formula in second-order predicate logic?
- $\exists x \forall y P(x, y)$
- $\forall x \exists y P(x, y)$
- $\exists P \forall x P(x)$
- $\forall P \exists x P(x)$
What is the Löwenheim–Skolem theorem?
- A theorem that states that every first-order theory has a model of every infinite cardinality.
- A theorem that states that every second-order theory has a model of every infinite cardinality.
- A theorem that states that every first-order theory has a model of every finite cardinality.
- A theorem that states that every second-order theory has a model of every finite cardinality.
What is the Compactness theorem?
- A theorem that states that every consistent set of first-order sentences has a model.
- A theorem that states that every consistent set of second-order sentences has a model.
- A theorem that states that every consistent set of first-order sentences has a finite model.
- A theorem that states that every consistent set of second-order sentences has a finite model.
What is the Completeness theorem?
- A theorem that states that every valid formula in first-order predicate logic is provable.
- A theorem that states that every valid formula in second-order predicate logic is provable.
- A theorem that states that every satisfiable formula in first-order predicate logic is provable.
- A theorem that states that every satisfiable formula in second-order predicate logic is provable.
What is the Gödel's incompleteness theorem?
- A theorem that states that every consistent first-order theory is either incomplete or unsound.
- A theorem that states that every consistent second-order theory is either incomplete or unsound.
- A theorem that states that every consistent first-order theory is either complete or unsound.
- A theorem that states that every consistent second-order theory is either complete or unsound.
What is the difference between a model and an interpretation in second-order predicate logic?
- A model is a set of individuals and an interpretation is a function that assigns a truth value to each formula.
- A model is a set of properties and an interpretation is a function that assigns a truth value to each formula.
- A model is a set of individuals and an interpretation is a function that assigns a property to each individual.
- A model is a set of properties and an interpretation is a function that assigns a property to each property.
What is the difference between a theory and a model in second-order predicate logic?
- A theory is a set of formulas and a model is a set of individuals that satisfies the formulas in the theory.
- A theory is a set of formulas and a model is a set of properties that satisfies the formulas in the theory.
- A theory is a set of individuals and a model is a set of formulas that is true for all individuals in the theory.
- A theory is a set of properties and a model is a set of formulas that is true for all properties in the theory.
What is the difference between a satisfiability and a validity in second-order predicate logic?
- A formula is satisfiable if there exists a model in which the formula is true, and a formula is valid if it is true in all models.
- A formula is satisfiable if there exists a model in which the formula is false, and a formula is valid if it is false in all models.
- A formula is satisfiable if there exists a model in which the formula is true, and a formula is valid if it is false in all models.
- A formula is satisfiable if there exists a model in which the formula is false, and a formula is valid if it is true in all models.
What is the difference between a first-order language and a second-order language?
- A first-order language contains only individual variables, while a second-order language contains both individual variables and predicate variables.
- A first-order language contains only predicate variables, while a second-order language contains both individual variables and predicate variables.
- A first-order language contains only individual variables and function symbols, while a second-order language contains both individual variables and predicate variables.
- A first-order language contains only predicate variables and function symbols, while a second-order language contains both individual variables and predicate variables.
What is the difference between a first-order theory and a second-order theory?
- A first-order theory is a set of formulas in a first-order language, while a second-order theory is a set of formulas in a second-order language.
- A first-order theory is a set of formulas in a second-order language, while a second-order theory is a set of formulas in a first-order language.
- A first-order theory is a set of formulas in a first-order language that contains only individual variables, while a second-order theory is a set of formulas in a second-order language that contains both individual variables and predicate variables.
- A first-order theory is a set of formulas in a second-order language that contains both individual variables and predicate variables, while a second-order theory is a set of formulas in a first-order language that contains only individual variables.
What is the difference between a first-order model and a second-order model?
- A first-order model is a set of individuals and an interpretation that assigns a truth value to each formula in a first-order language, while a second-order model is a set of properties and an interpretation that assigns a truth value to each formula in a second-order language.
- A first-order model is a set of properties and an interpretation that assigns a truth value to each formula in a first-order language, while a second-order model is a set of individuals and an interpretation that assigns a truth value to each formula in a second-order language.
- A first-order model is a set of individuals and an interpretation that assigns a property to each individual, while a second-order model is a set of properties and an interpretation that assigns a property to each property.
- A first-order model is a set of properties and an interpretation that assigns a property to each individual, while a second-order model is a set of individuals and an interpretation that assigns a property to each property.
What is the difference between a first-order satisfaction and a second-order satisfaction?
- A formula is first-order satisfiable if there exists a first-order model in which the formula is true, and a formula is second-order satisfiable if there exists a second-order model in which the formula is true.
- A formula is first-order satisfiable if there exists a second-order model in which the formula is true, and a formula is second-order satisfiable if there exists a first-order model in which the formula is true.
- A formula is first-order satisfiable if there exists a first-order model in which the formula is false, and a formula is second-order satisfiable if there exists a second-order model in which the formula is false.
- A formula is first-order satisfiable if there exists a second-order model in which the formula is false, and a formula is second-order satisfiable if there exists a first-order model in which the formula is false.
What is the difference between a first-order validity and a second-order validity?
- A formula is first-order valid if it is true in all first-order models, and a formula is second-order valid if it is true in all second-order models.
- A formula is first-order valid if it is true in all second-order models, and a formula is second-order valid if it is true in all first-order models.
- A formula is first-order valid if it is false in all first-order models, and a formula is second-order valid if it is false in all second-order models.
- A formula is first-order valid if it is false in all second-order models, and a formula is second-order valid if it is false in all first-order models.