Skip to content
Carmelics
TopicsThinkersChangesContributorsLoading account…

    Carmelics

    A reasoning platform. Break down any belief into clear reasons, explore both sides, and weigh the evidence honestly.

    Navigate

    • Topics
    • Search
    • Recent Changes
    • Contribute
    • How It Works
    • Glossary
    • Thinkers
    • Contributors
    • About
    • Statistics
    • Terms
    • Privacy

    Database

    Statements
    —
    Perspectives
    —
    Topics
    —

    Press ? for keyboard shortcuts

    LoyalLoyalJusticeJustice
    Made withinDC&Austin
    G_F is provably equivalent to the universal formula ∀x¬Pr... — Carmelics
    Statements
    321,452
    Perspectives
    108,905
    Topics
    42
    Home/Modality & Possibility
    HistoryEditSee Inverse

    Part of a larger discussion

    Supports→The Gödel sentence G_F is true (when F is consistent and the provability predicate is a Σ⁰₁-formula)

    G_F is provably equivalent to the universal formula ∀x¬Prf_F(x, ⌈G_F⌉) when the provability predicate Prov_F(x) is chosen as a Σ⁰₁-formula

    Modality & PossibilityTruth & Knowledge
    ?Rate how convincing each reason is below to see the overall strength.

    No one has weighed in yet. Be the first to share reasons for or against this statement.

    Sign in or register to share your perspective on this statement.

    Topics

    Modality & PossibilityTruth & Knowledge

    Related

    F is assumed to be consistentF ⊢ Prf_F(n̲, ⌈G_F⌉) would contradict Gödel's incompleteness theoremIf G_F were false, there would be a number n such that F ⊢ Prf_F(n̲, ⌈G_F⌉)The Gödel sentence G_F is true (when F is consistent and the provability predica...

    Next step

    Based on where you are in your exploration

    Browse more in Modality & Possibility
    Related propositions within the same area of thought.
    +1 moreShow less
    Universal formulas of this form can be proved false whenever they are in fact fa...

    Similar

    The Gödel sentence G_F is true (when F is consistent and the provabili...82%The Completeness Theorem uses the concept of a first-order structure, ...79%If Cons(F) were provable in F, then the Gödel sentence G_F would also ...77%Δ¹₁-formulas are those second-order formulas that are logically equiva...77%

    Source

    AI-extracted
    SEP: goedel-incompleteness
    View source passageHide passage
    In fact, in favourable circumstances, it can be shown that \(G_F\) is true, provided that \(F\) is indeed consistent. This is the case if, for example, the provability predicate \(\Prov_F (x)\) has been chosen as a \(\Sigma^{0}_1\)-formula: The Gödel sentence is then provably equivalent to the universal formula \(\forall x\neg\Prf_F (x, \ulcorner G_F\urcorner)\). Such formulas can be proved false whenever they in fact are false: if false, there would be a number \(\boldsymbol{n}\) such that \(F

    Details

    Type
    premise
    Perspectives
    0 (0 for, 0 against)
    Edits
    1 edit

    Open for perspectives

    This idea is waiting for its first supporting or challenging perspective.

    Share the first perspective