IFV \(\mathrm{IFV}\) — Binary Free-Variable Occurrence Predicate (Fm.IFV, Ctx.IFV, ClassTerm.IFV, AST Constructor: TpIFV / TpCtxIFV)
Type-qualified binary syntactic hygiene predicate Fm.IFV(v, 𝛙), Ctx.IFV(v, Γ), ClassTerm.IFV(v, k) taking two arguments and asserting that variable v occurs free in the formula 𝛙, context Γ, or class term k (used instead of x ∈ Fm.FV(𝛙)).
| Field | Mathematical & Kernel Specification (MKTD1 / MKTD2) |
|---|---|
| Symbol |
IFV
\(\mathrm{IFV}\)
|
| 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 | Variable × A.Expression → Bool |
| Binder Status | See Category & Signature above |
| Defining Kernel Entries (ML Labels) | See Related Symbols & Kernel Entries below. |
| LaTeX Form | \mathrm{IFV} |
| How to Understand It | SML AST Constructor: |
| Canonical Law / Usage | (¬Fm.IFV(v, 𝛙)) , (¬Ctx.IFV(v, Γ)) |
| Related Symbols & Kernel Entries |