[The IFF Metashell Meta Namespace]

Construction Steps

  • Winter 2007 (Nov–Feb): The type level namespace is being expanded by including a structural component (along with the already existing core component) consisting of an axiomatization for “the category of categories”. This includes axiomatizations for graphs, categories, functors, natural transformations, adjunctions and monads. In order to accomplish this, we need only modify the previous IFF axiomatizations for category theory (4 October 2001 and 2 January 2002), written in the experimental phase of development.
  • Spring 2008 (Mar–June): The specialization of the type level into the meta level will be encoded: the kernel (set, function, span, predicate and relation namespaces) and the diagram and limit namespaces. A special goal is the definition of parametric composition* using 2-dimensional membership and proof (spans and relations).
  • Summer 2008 (July–Sept): The fiber structure will be greatly expanded. This consists of completing the axiomatizations for the slice category structures for functions and spans, the subobject structures for predicates and relations, and the links and connections between these four concepts.
  • Fall 2008 (Oct–Dec): The exponent namespace will be axiomatized. The impact on the other parts of the meta level will need to be assessed and implemented. The colimit namespace also needs to be axiomatized. Furthermore, the axiomatization for specific finite limits/colimits needs to be augmented by an axiomatization for general limits/colimits.
*The IFF is a category theoretic metatheory. Composition is at the heart of category theory. Parametric composition is in one sense the “true” composition, since it operates on generalized pairs (spans) of functions.

Overview

The meta namespace of the IFF metashell (IFF-META) is a large-sized namespace (~ 2000 terms, with ~ 500 terms in the kernel) located directly below the IFF-TYPE namespace and directly above the natural part of the IFF. It enables declarations of all natural things. Below we list the complete terminology for the IFF-META namespace (emphasized terms were previously introduced in the IFF-TYPE namspace). Look into the linked PDF files for more detailed comments and the axiomatization. The IFF-META namespace consists of five nested namespaces: kernel, finite diagrams, finite limits, finite colimits and exponent namespaces.

kernel
The kernel nested namespace continues the axiomatization for the basic collections of sets and functions, and initiates the axiomatization for the other core concepts. By introducing basic terminology, it defines at the meta level a finitely-complete category Set of Cantorian featureless sets and functions enriched with factorization and subobjects.
  • There is an outer namespace for terms relating to the category theory of the kernel. The namespace terminology is listed in Table 1. This consists of 8 terms and concepts representing Set the category of sets and functions, Rel the category of sets and (binary) relations, connecting adjoint functors (f2rr2f, η = {-}, ε)  : Set → Rel, and the generated power monad P = (P = f2r ∘ r2f, {-}, ∪).

Natural

CategoryFunctorTransformationAdjunctionMonad
setftn2rel
relrel2ftn
powersingleton unionpower

Technical Prefix: meta
Recommended Prefix: meta

Table 3: The Meta Outer Namespace
  • The set namespace terminology is listed in Table 3. This consists of 42 terms and 36 concepts (6 synonyms) representing the set basic collection and its components, and subobject structure.

Type SetType Function
.set
basicsset isomorphic-relation
[in]finite-set

binary-(union | intersection) difference
instanceszero = initial = empty
one = terminal two three
constant-zero constant-one
counique unique
subobjectsubset-relationsmaller larger inclusion predicate
power power-pair
leq bottom top binary-(join | meet)
minus complement implication
singleton union = join intersection = meet


exists = power inverse-image forall

Technical Prefix: meta.krnl
Recommended Prefix: meta

Table 3: The Meta Set Namespace
  • The function namespace terminology is listed in Table 4. This consists of 57 terms and concepts representing the concepts of function, function (optimal-)restriction order, composition functionality, element, application functionality, factorization, conversion to other kinds, function morphism and belonging order.

Type SetType Function
.ftn
basicsfunction
[optimal-]restriction-relation
source target
[optimal-](smaller | larger)

element
constant-function
set
constant-element construction
category theorycomposable-pairfactor0 factor1 composition identity

appliable-pairelement-factor function-factor
application
factorization
injection
surjection
bijection
range kernel coimage
injective-factor coapplication
surjective-factor coequalizer
inverse
conversion
predicate span relation fiber unit
instances
initial terminal counique unique


.ftn.mor
basics2-cell
belonging
equivalence isomorphism
source target function
element0 element1
category theorycomposable-pairfactor0 factor1 composition identity

Technical Prefix: meta.krnl
Recommended Prefix: meta

Table 4: The Meta Function Namespace
finite diagrams
The finite diagram nested namespace essentially defines four categories of diagrams (Figure 4): the category Set2 of set pairs and function pairs (diagrams for binary products), the category Set3 of set triples and function triples (diagrams for ternary products), the (comma) category Ppr = (ΔΔ) of parallel pairs and parallel pair morphisms (diagrams for equalizers), and the (comma) category Ospn = (1Δ) of opspans and opspan morphisms (diagrams for pullbacks).
The diagram namespace terminology is listed in Table 8. This consists of 91 terms and 85 concepts (6 synonyms) representing the four basic kinds of things (Set2, Set3, Ppr, Ospn) and their components, category theory, and conversion maps.

Table 8: The Meta Finite Diagram Namespace
finite limits
The limit namespace terminology of this namespace, which is listed in Table 9, consists of 131 terms and 131 concepts (with no synonyms). There are six kinds of limit according to diagram shape: binary and ternary products and their power variants, equalizers and pullbacks.

Table 9: The Meta Finite Limit Namespace

In the meta namespace, a large part of the kernel is the specialization (using subset, delimitation, (optimal-)restriction and abridgment) of the type namespace kernel. The meta namespace initiates axiomatization for exponents.

[The IFF Meta Namespace Architecture]
Figure 1: The IFF Meta Namespace Architecture

In the current phase of IFF development, the old IFF Upper Core (meta) Ontology (IFF-UCO) has moved up and become the kernel of the metashell namespace (IFF-META). Like the axiomatization for finite type limits and the axiomatization for finite limits of categories and functors, this axiomatization is in adjunctive form. The IFF-META namespace plays a central role in the IFF axiomatization — it is the most referenced namespace at the metalevel. The architecture of the IFF-META namespace is illustrated in Figure 1. The IFF-META kernel consists of the axiomatization for metasets, metapredicates and metafunctions. At the metashell meta level the axiomatization for relations, which includes order-theoretic concepts, has branched off into a namespace in its on right. The kernel and limit namespace axiomatizations are essentially copies of those in the type level namespace (IFF-TYPE). These axiomatizations rely heavily upon the subset, delimitation, restriction and abridgement relations for sets, predicates, functions and relations, respectively. The colimit namespace is a categorical dual to the limit namespace. The exponent namespace axiomatization is new.