DefMetaConecessitation (4.03, Inference Rule): CoNecessitation(meta,WIP)

Standalone kernel entity record from 4. Metalogical Laws (4.01–4.06) — View in Complete Entity Database (#DefMetaConecessitation) →

Formula Display:
Proof Trees:

DefMetaConecessitation (4.03) — CoNecessitation(meta,WIP)

Explicit substitution, context encoding, co-necessitation, uniqueness quantifiers, and reflected comprehension.

Num Entity Database Record (Vertical Field Table)
4.03
Title CoNecessitation(meta,WIP) #DefMetaConecessitation #label-conecessitation-meta-wip
Classification Inference Rule
Formula
0\(\href{../symbols/delimiters-brackets.html}{(} \href{../symbols/forall-binder.html}{\forall} \href{../symbols/delimiters-brackets.html}{(} \href{../symbols/formula-metavariables.html}{\Gamma} \href{../symbols/typing-colon.html}{:} \href{../symbols/ctx-sort.html}{\mathsf{Ctx}} \href{../symbols/delimiters-brackets.html}{)} \href{../symbols/forall-binder.html}{\forall} \href{../symbols/delimiters-brackets.html}{(} \href{../symbols/formula-metavariables.html}{\boldsymbol{\varphi}} \href{../symbols/typing-colon.html}{:} \href{../symbols/fm-sort.html}{\mathsf{Fm}} \href{../symbols/delimiters-brackets.html}{)} \href{../symbols/delimiters-brackets.html}{(} \href{../symbols/delimiters-brackets.html}{(} \href{../symbols/theory-fau.html}{\mathcal{F}} \href{../symbols/comma-delim.html}{,} \href{../symbols/empty-list-const.html}{[\,]} \href{../symbols/turnstile-derivability.html}{\vdash} \href{../symbols/quotation.html}{\langle } \href{../symbols/theory-fau.html}{\mathcal{F}} \href{../symbols/comma-delim.html}{,} \href{../symbols/formula-metavariables.html}{\Gamma} \href{../symbols/turnstile-derivability.html}{\vdash} \href{../symbols/formula-metavariables.html}{\boldsymbol{\varphi}} \href{../symbols/quotation.html}{\rangle } \href{../symbols/delimiters-brackets.html}{)} \href{../symbols/impl-conn.html}{\rightarrow} \href{../symbols/delimiters-brackets.html}{(} \href{../symbols/theory-fau.html}{\mathcal{F}} \href{../symbols/comma-delim.html}{,} \href{../symbols/formula-metavariables.html}{\Gamma} \href{../symbols/turnstile-derivability.html}{\vdash} \href{../symbols/formula-metavariables.html}{\boldsymbol{\varphi}} \href{../symbols/delimiters-brackets.html}{)} \href{../symbols/delimiters-brackets.html}{)} \href{../symbols/delimiters-brackets.html}{)} \)
SML Kernel AST PCredo_prf
Scheme of Types 0(βˆ€([Ξ“@Variable]:[Ctx@Type])βˆ€([𝛗@Variable]:[Fm@Type])((𝘍,[]βŠ’β€Ήπ˜,[Ξ“@Ctx.Expression]⊒[𝛗@Fm.Expression]β€Ί)β†’(𝘍,[Ξ“@Ctx.Expression]⊒[𝛗@Fm.Expression])))
Kernel Note If a formula < 𝘍,Ξ“βŠ’π›—> is derived in 𝘍 from the empty context, then the formula 𝛗 is derived in 𝘍 from the context Ξ“. Why this holds for 𝘍: for an arbitrary theory 𝘞, concluding (𝘞, Ξ“βŠ’π›—) from (𝘞, [] ⊒ <𝘞, Ξ“βŠ’π›—>) requires 1-consistency / Σ₁-soundness of 𝘞 (and for the r.e. base theory π˜›, asserting internal co-necessitation would by LΓΆb's theorem 5.01 trivialize π˜›). Because 𝘍 is a non-r.e. sound Henkin extension equipped with Soundness 3.73 ((𝘍, [] ⊒ ψ) β†’ ⟦ψ⟧), instantiating 3.73 at ψ := <𝘍, Ξ“βŠ’π›—> directly yields (𝘍, Ξ“βŠ’π›—).
Verification Primitive / Derived Rule (Kernel) · Standalone Entry (DefMetaConecessitation) → · (4.03) · #DefMetaConecessitation