Rosser’s trick in incompleteness proofs
E943475
Rosser’s trick in incompleteness proofs is a refinement of Gödel’s incompleteness argument that strengthens the result by avoiding the need for the assumption that the underlying formal system is ω-consistent.
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
method in mathematical logic
ⓘ
proof technique ⓘ refinement of Gödel’s incompleteness argument ⓘ |
| appearsIn |
expositions of incompleteness theorems
ⓘ
standard textbooks on mathematical logic ⓘ |
| appliesTo |
Peano arithmetic
NERFINISHED
ⓘ
formal arithmetic ⓘ sufficiently strong recursively axiomatized theories ⓘ |
| assumptionRequired | simple consistency ⓘ |
| assumptionWeakened | ω-consistency ⓘ |
| avoids | use of ω-consistency in the incompleteness proof ⓘ |
| category |
self-reference constructions in logic
ⓘ
techniques in incompleteness proofs ⓘ |
| consequence | every consistent, effectively axiomatized, sufficiently strong theory is incomplete ⓘ |
| contrastWith | Gödel’s original use of ω-consistency ⓘ |
| ensures | existence of a sentence undecidable under mere consistency ⓘ |
| field |
mathematical logic
ⓘ
metamathematics ⓘ proof theory ⓘ |
| formalProperty | constructs a sentence undecidable if the theory is consistent ⓘ |
| historicalContext | developed after Gödel’s 1931 incompleteness theorems ⓘ |
| influenced | later refinements of incompleteness theorems ⓘ |
| involves |
construction of a Rosser sentence
ⓘ
formalization of proof length comparisons ⓘ |
| keyIdea |
encode a statement that any proof of the sentence has a shorter proof of its negation
ⓘ
use of a sentence comparing proofs of itself and its negation ⓘ |
| logicalFramework | first-order arithmetic ⓘ |
| modifies | Gödel’s original self-referential sentence construction ⓘ |
| namedAfter | J. Barkley Rosser NERFINISHED ⓘ |
| relatedConcept |
Gödel sentence
NERFINISHED
ⓘ
Rosser sentence ⓘ |
| relatedTo |
Hilbert’s program
NERFINISHED
ⓘ
limitations of formal systems ⓘ |
| reliesOn |
Gödel numbering
NERFINISHED
ⓘ
arithmetization of syntax ⓘ representability of provability in arithmetic ⓘ |
| requires |
ability to formalize provability predicates
ⓘ
ability to reason about proofs within the theory ⓘ |
| strengthens | Gödel’s first incompleteness theorem NERFINISHED ⓘ |
| typicalAssumptionOnTheory |
recursively enumerable axioms
GENERATED
ⓘ
sufficient arithmetic strength to represent primitive recursive functions GENERATED ⓘ |
| usedFor |
avoiding the ω-consistency assumption
ⓘ
proving incompleteness results ⓘ |
| usedIn | Rosser’s incompleteness theorem NERFINISHED ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.