Category Theory Structure Rank Skill
Ranked taxonomy of categorical structures from sets to ∞-topoi with gap analysis and DuckDB integration.
Trit: 0 (ERGODIC) — Coordinator mapping structures to skills
Structure Hierarchy
Level 0: Foundations
| Structure | Skill | Coverage | Gap |
|-----------|-------|----------|-----|
| Sets | (implicit) | ✓ | — |
| Functions | (implicit) | ✓ | — |
| Relations | acsets-relational-thinking | ✓ | — |
Level 1: Basic Categories
| Structure | Skill | Coverage | Gap |
|-----------|-------|----------|-----|
| Categories | ctp-yoneda | ✓ | — |
| Functors | naturality-factor | ✓ | — |
| Natural Transformations | naturality-factor | ✓ | — |
| Yoneda Lemma | yoneda-directed | ✓ | — |
Level 2: Enriched & Internal
| Structure | Skill | Coverage | Gap |
|-----------|-------|----------|-----|
| Enriched Categories | elements-infinity-cats | ◐ | Need dedicated skill |
| Monads | free-monad-gen | ✓ | — |
| Adjunctions | galois-connections | ✓ | — |
| Elementary Topoi | effective-topos | ✓ | — |
Level 3: Higher Structures
| Structure | Skill | Coverage | Gap |
|-----------|-------|----------|-----|
| Double Categories | cat-tripartite | ◐ | Partial in CatColab |
| Bicategories | — | ✗ | MAJOR GAP |
| Operads | operad-compose | ✓ | — |
| Polynomial Functors | asi-polynomial-operads | ◐ | Spivak lectures incomplete |
| Actegories | unwiring-arena | ◐ | Implicit only |
Level 4: Homotopical
| Structure | Skill | Coverage | Gap |
|-----------|-------|----------|-----|
| Quasi-categories | elements-infinity-cats | ✓ | — |
| Segal Spaces | segal-types | ✓ | — |
| Complete Segal Spaces | rezk-types | ✓ | — |
| ∞-Cosmos | elements-infinity-cats | ✓ | — |
| Dendroidal Sets | infinity-operads | ◐ | Need formalization |
Level 5: ∞-Topoi
| Structure | Skill | Coverage | Gap |
|-----------|-------|----------|-----|
| ∞-Categories | infinity-topos | ✓ | — |
| ∞-Topoi | infinity-topos | ✓ | — |
| Higher Topos Theory | infinity-topos | ◐ | Lurie's HTT not fully extracted |
| Synthetic ∞-Cat | riehl-post-rigorous | ◐ | Rzk formalization ongoing |
Coverage Legend
✓ = Good coverage (skill exists, comprehensive)
◐ = Partial coverage (skill exists, gaps remain)
✗ = No coverage (major gap, needs skill)
Major Gaps Identified
1. Bicategories (Level 3)
Status: ✗ No dedicated skill
Impact: High — bridges double categories and ∞-cosmos
Remedy: Create bicategory skill from:
- Street's "Fibrations in Bicategories"
- Bénabou's original work
- Link to
cat-tripartiteandtopos-catcolab
2. Polynomial Functors (Level 3)
Status: ◐ Partial in asi-polynomial-operads
Impact: High — Spivak's key contribution
DuckDB: /Users/bob/ies/spivak_poly.duckdb (empty lectures table)
Remedy: Extract from Spivak lectures, populate DuckDB
3. Dendroidal Sets (Level 4)
Status: ◐ Mentioned but not formalized Impact: Medium — ∞-operads foundation Remedy: Create dedicated skill with:
- Moerdijk-Weiss construction
- Link to
infinity-operads
4. HTT Extraction (Level 5)
Status: ◐ Lurie's Higher Topos Theory not fully extracted Impact: Very High — foundational reference Remedy: MathPix extraction of key chapters
DuckDB Sources
| Database | Tables | Relevance |
|----------|--------|-----------|
| hatchery_category.duckdb | concept_graph, concept_paths | Concept relationships |
| spivak_poly.duckdb | spivak_poly_lectures | Polynomial functors |
| dendroidal.duckdb | dendroidal | Tree structures |
| mermaid_acset.duckdb | — | Diagram persistence |
| hatchery_topology.duckdb | — | Topological structures |
Query: Concept Graph
-- Find category-theoretic concepts
SELECT source_concept, relation, target_concept
FROM concept_graph
WHERE source_concept IN ('Actegory', 'Dendroidal Sets', 'Galois Connection')
ORDER BY source_concept;
Query: Structure Dependencies
-- Build structure dependency graph
WITH RECURSIVE deps AS (
SELECT source_concept, target_concept, 1 as depth
FROM concept_graph
WHERE source_concept = 'Dendroidal Sets'
UNION ALL
SELECT g.source_concept, g.target_concept, d.depth + 1
FROM concept_graph g
JOIN deps d ON g.source_concept = d.target_concept
WHERE d.depth < 5
)
SELECT * FROM deps;
GF(3) Trit Assignment by Level
| Level | Trit | Role | Example | |-------|------|------|---------| | 0-1 | -1 | Foundation/Constraint | Sets, Categories | | 2-3 | 0 | Transport/Enrichment | Monads, Operads | | 4-5 | +1 | Generation/Extension | ∞-Categories, Synthetic |
Conservation: Each level transition preserves GF(3) sum.
Intercept Points (SNPs = Skill Navigation Points)
High-Value Intercepts
| From | To | Skill Bridge | Value |
|------|-----|--------------|-------|
| Operads → ∞-Operads | operad-compose → infinity-operads | Dendroidal embedding | ★★★ |
| Topos → ∞-Topos | effective-topos → infinity-topos | Lurie characterization | ★★★ |
| Adjunction → Kan Extension | galois-connections → kan-extensions | Universal property | ★★★ |
| Double Cat → ∞-Cosmos | cat-tripartite → elements-infinity-cats | Formal category theory | ★★ |
| Polynomial → Operad | asi-polynomial-operads → operad-compose | Spivak construction | ★★ |
Unclear/Disputed Areas
| Area | Issue | Skills Involved |
|------|-------|-----------------|
| Model independence | When does ∞-cosmos suffice vs concrete model? | riehl-post-rigorous, elements-infinity-cats |
| Synthetic foundations | HoTT vs Book HoTT vs Rzk | riehl-post-rigorous, segal-types |
| Operad coloring | GF(3) vs arbitrary coloring for operads | infinity-operads, gay-mcp |
| Actegory ↔ Module | Terminological confusion | unwiring-arena, operad-compose |
Grandis/Grossberg Connections
Marco Grandis (Directed Algebraic Topology)
- d-spaces: Spaces with distinguished directed paths
- Link:
directed-interval,covariant-fibrations - Gap: No dedicated Grandis skill
Steven Grossberg (Adaptive Resonance Theory)
- ART: Attractor dynamics in neural networks
- Link:
alife,attractor,equilibrium - Gap: Need bridge to categorical learning theory
Skill Creation Priority
| Priority | Gap | Estimated Effort | |----------|-----|------------------| | 1 | Bicategories | Medium | | 2 | Polynomial functors (complete) | High | | 3 | HTT extraction | Very High | | 4 | Dendroidal formalization | Medium | | 5 | Grandis d-spaces | Low |
Commands
# Query concept graph
duckdb /Users/bob/ies/hatchery_category.duckdb \
-c "SELECT * FROM concept_graph WHERE relation = 'uses';"
# Check Spivak lectures
duckdb /Users/bob/ies/spivak_poly.duckdb \
-c "SELECT COUNT(*) FROM spivak_poly_lectures;"
# Find skill gaps
grep -l "TODO\|FIXME\|GAP" ~/.claude/skills/*/SKILL.md
Related Skills
ctp-yoneda- Basic category theoryelements-infinity-cats- Riehl-Verity ∞-cosmosinfinity-topos- ∞-topos integrationoperad-compose- Operadic compositionriehl-post-rigorous- Formalization strategiesasi-polynomial-operads- Polynomial/operad bridge
Autopoietic Marginalia
The interaction IS the skill improving itself.
Every use of this skill is an opportunity for worlding:
- MEMORY (-1): Record what was learned
- REMEMBERING (0): Connect patterns to other skills
- WORLDING (+1): Evolve the skill based on use
Add Interaction Exemplars here as the skill is used.