NFV \(\mathrm{NFV}\) — Non-Free-Variable Hygiene Predicate (NFV, AST Constructor: TpNFV)
Metalevel-1 syntactic hygiene predicate NFV(X, x, (𝛃:Fm)) asserting that variable x of sort X does not occur free in formula 𝛃 : Fm.
| Field | Mathematical & Kernel Specification (MKTD1 / MKTD2) |
|---|---|
| Symbol |
NFV
\(\mathrm{NFV}\)
|
| Category | Predicate Symbol (Metatheoretic Side-Condition Predicate) |
| SML AST Constructor | Kernel AST Symbol / Sort Constructor in typetheory.ML (Class_p / Truth_p / EXP / UCol) |
| Constructor Arguments | Typed arguments as specified by the Signature / Sort field above |
| Metatype / Signature | Type × Variable × Fm → Bool |
| Binder Status | See Category & Signature above |
| Defining Kernel Entries (ML Labels) | See Related Symbols & Kernel Entries below. |
| LaTeX Form | \mathrm{NFV} |
| How to Understand It | SML AST Constructor: |
| Canonical Law / Usage | NFV(X, x, (𝛃:Fm)) |
| Related Symbols & Kernel Entries |