dedekind::category::ImageChi< F > Struct Template Reference

The characteristic predicate of image_of(F) — recognises y as "in the image of @c F". More...

Collaboration diagram for dedekind::category::ImageChi< F >:

Public Types
using	Domain = Cod<F>
using	Codomain = Ternary

Public Member Functions
constexpr Ternary	operator() (const Cod< F > &) const noexcept
	Default Honest-Rejection classifier: returns Ternary::Unknown. Specialisations on specific F fire the True / False answer; until then, the image is honestly opaque.

Public Attributes
F	f

Detailed Description

template<typename F>
requires IsArrow<F>
struct dedekind::category::ImageChi< F >

The characteristic predicate of image_of(F) — recognises y as "in the image of @c F".

Default behaviour: returns Ternary::Unknown because the existential ∃x ∈ Dom<F>. F(x) = y is undecidable on a general IsArrow without further structure on Dom<F> (e.g. finite enumerability, inversion, or a comprehension-DSL hook). Concrete specialisations override for specific F — Slice 4 lands the mod_n case, where the image is the interval [0, n).

Template Parameters

F	The arrow whose image this predicate classifies.

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The documentation for this struct was generated from the following file:

• src/main/modules/dedekind/category/image.cppm