Herbrand expansion

E238236

Herbrand expansion is a method in mathematical logic that transforms first-order formulas into equivalent (often infinite) propositional combinations by systematically instantiating quantified variables with terms from the Herbrand universe.

All labels observed (1)

Label Occurrences
Herbrand expansion canonical 3

How this entity was disambiguated

Statements (42)

Predicate Object
instanceOf method in mathematical logic
technique in proof theory
appliesTo Skolemized formulas
prenex form formulas
assumes classical first-order logic semantics
basedOn syntactic generation of ground instances
canBe countably infinite for general first-order theories
finite for some formulas
closelyRelatedTo Herbrand disjunction
Herbrand interpretation
componentOf Herbrand’s approach to first-order validity
contrastsWith semantic methods using structures directly
field mathematical logic
proof theory
goal eliminate quantifiers by instantiation
reduce first-order validity to propositional validity
historicalContext introduced in early 20th century
implies existence of a finite unsatisfiable subset for unsatisfiable formulas
inputType first-order formula
namedAfter Jacques Herbrand
outputType propositional combination of ground instances
property logically equivalent to original first-order formula
often infinite expansion
relatedTo Herbrand base
Herbrand's theorem
surface form: Herbrand theorem

Herbrand universe
Skolemization
first-order logic
propositional logic
requires enumeration of Herbrand universe terms
step construct Herbrand universe from function and constant symbols
form disjunctions and conjunctions of ground instances
generate ground terms from Herbrand universe
instantiate quantified variables with ground terms
usedFor reducing first-order entailment to propositional entailment
showing completeness of certain proof calculi
usedIn automated theorem proving
resolution-based proof methods
satisfiability testing for first-order formulas
uses Herbrand universe
ground terms
instantiation of quantified variables

How these facts were elicited

Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Jacques Herbrand knownFor Herbrand expansion
Herbrand disjunction relatedTo Herbrand expansion