Rosser trick
E943471
The Rosser trick is a refinement of Gödel’s incompleteness proof that avoids using ω-consistency by constructing a self-referential sentence asserting that a shorter proof of its negation exists.
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
method in mathematical logic
ⓘ
proof technique ⓘ refinement of Gödel’s incompleteness proof ⓘ |
| appearsIn |
expositions of incompleteness theorems
ⓘ
standard textbooks on mathematical logic ⓘ |
| appliesTo |
formal arithmetic
ⓘ
recursively axiomatized theories ⓘ sufficiently strong consistent theories ⓘ |
| assumes | consistency ⓘ |
| avoidsAssumption | ω-consistency ⓘ |
| basedOn |
Gödel numbering
NERFINISHED
ⓘ
diagonalization ⓘ |
| constructs |
Rosser sentence
NERFINISHED
ⓘ
self-referential sentence ⓘ |
| differsFrom | Gödel’s original construction by using proof-length comparison ⓘ |
| ensures |
if theory is consistent, Rosser sentence is undecidable
ⓘ
no proof of the Rosser sentence exists without a shorter proof of its negation ⓘ no proof of the negation exists without a shorter proof of the sentence ⓘ |
| field |
mathematical logic
ⓘ
metamathematics ⓘ proof theory ⓘ |
| generalizes | Gödel’s first incompleteness theorem NERFINISHED ⓘ |
| hasConsequence | even mere consistency implies incompleteness for strong enough theories ⓘ |
| historicalContext | developed after Gödel’s 1931 incompleteness theorems ⓘ |
| influenced |
later work on provability logic
ⓘ
refinements of incompleteness theorems ⓘ |
| involves |
coding of finite sequences
ⓘ
formalization of provability within arithmetic ⓘ partial truth definitions for arithmetic ⓘ primitive recursive relations ⓘ |
| keyIdea |
compare lengths of proofs of a sentence and its negation
ⓘ
encode proof minimality into the sentence ⓘ sentence asserts existence of a shorter proof of its negation ⓘ |
| logicalProperty | yields a sentence independent of the theory if the theory is consistent ⓘ |
| namedAfter | J. Barkley Rosser NERFINISHED ⓘ |
| namedInHonorOf | J. Barkley Rosser NERFINISHED ⓘ |
| relatesTo | Gödel sentence NERFINISHED ⓘ |
| requires |
arithmetization of syntax
ⓘ
effective proof predicate ⓘ |
| strengthens | hypotheses of Gödel’s original incompleteness proof ⓘ |
| typicalDomain |
first-order arithmetic
ⓘ
theories extending Robinson arithmetic ⓘ |
| usedFor |
proving incompleteness of Peano arithmetic
ⓘ
proving incompleteness of stronger arithmetic theories ⓘ removing ω-consistency from incompleteness assumptions ⓘ |
| usedInProofOf |
Rosser’s incompleteness theorem
NERFINISHED
ⓘ
first incompleteness theorem without ω-consistency ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.