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 5

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 theorem ⓘ
linked to: Herbrand's 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 (5)

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

Jacques Herbrand → knownFor → Herbrand expansion ⓘ
Herbrand disjunction → relatedTo → Herbrand expansion ⓘ
Skolemization → appliedBefore → Herbrand expansion ⓘ