# Lojban

> Lojban: the logical language designed for unambiguous machine-parseable human expression with perfect IPA correspondence.

- Skill: `plurigrid/lojban` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add plurigrid/lojban`
- Raw SKILL.md: https://api.skillmd.com/api/skills/plurigrid/lojban/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: plurigrid (https://skillmd.com/u/plurigrid)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/plurigrid/lojban

---

# Lojban Skill

> *".i la lojban. bangu lo ka ce'u logji"*
> — "Lojban is a language characterized by being logical"

Lojban: the logical language designed for unambiguous machine-parseable human expression with perfect IPA correspondence.

## Overview

**Lojban** (ISO 639-3: jbo) is a constructed language based on predicate logic, designed by the Logical Language Group (1987-1997) from James Cooke Brown's Loglan (1955).

**Key properties:**
- Unambiguous grammar (PEG-parseable)
- Culturally neutral vocabulary (from 6 source languages)
- 1:1 phoneme-grapheme correspondence
- Predicate-argument structure (selbri-sumti)

## GF(3) Classification

```
Trit: 0 (ERGODIC)
Role: Mediator between natural language chaos and formal logic
Conservation: Balanced self-referential structure
```

## Core Structures

### Gismu (Root Words)

1341 root predicates, each with defined place structure:

| Gismu | x₁ | x₂ | x₃ | x₄ | x₅ |
|-------|----|----|----|----|-----|
| **klama** | goer | destination | origin | route | vehicle |
| **tavla** | speaker | listener | subject | language | — |
| **djuno** | knower | fact | subject | epistemology | — |
| **gerku** | dog | breed | — | — | — |

### Selbri-Sumti Structure

```
   lo prenu    cu    klama    lo zarci
   ────────         ──────    ────────
     sumti₁         selbri     sumti₂
   (the person)    (goes-to)  (the market)
```

### IPA Correspondence

Lojban has perfect phoneme-grapheme mapping:

| Letter | IPA | Description |
|--------|-----|-------------|
| a | /a/ | open front |
| e | /ɛ/ | open-mid front |
| i | /i/ | close front |
| o | /o/ | close-mid back |
| u | /u/ | close back |
| y | /ə/ | schwa (buffer) |
| ' | /h/ | glottal separator |

Consonants map directly: p/b, t/d, k/g, f/v, s/z, c/j [ʃ/ʒ], x [x], m, n, l, r

## Causal Scale Mapping

| Level | Lojban Feature |
|-------|----------------|
| 0 (Total Order) | Unambiguous parse tree |
| 1 (Ordered Locale) | Place structure with open slots |
| 2 (Directed Locale) | Tense/aspect as directed modality |
| 3 (Causal Structure) | Logical connectives (ja, je, jo, ju) |
| 4 (Partial Causal) | Attitudinals (uncertainty markers) |
| 5 (Indefinite Causal) | Metalinguistic quotes (lu...li'u) |
| 6 (Process Matrix) | Self-referential predicates (logji) |

## SICP Connection

Lojban embodies SICP's metalinguistic abstraction (Chapter 4):

- **selbri** = procedure (predicate with place structure)
- **sumti** = arguments (fill places)
- **tanru** = compound predicates (composition)
- **abstraction** (nu, ka, du'u) = lambda over propositions

```scheme
;; SICP metacircular evaluator parallel:
(define (lojban-eval bridi environment)
  (cond ((selbri? bridi)
         (apply-selbri (operator bridi)
                       (list-of-sumti bridi)
                       environment))
        ((tanru? bridi)
         (compose-selbri (tanru-parts bridi)))
        ...))
```

## String Diagram Representation

```
        ┌─────────────┐
 x₁ ───→│             │───→ truth-value
        │   selbri    │
 x₂ ───→│  (klama)    │
        │             │
 x₃ ───→│             │
        └─────────────┘

Tanru composition:
        ┌──────┐     ┌──────┐
 x₁ ───→│sutra │────→│klama │───→ 
        └──────┘     └──────┘
         (fast)      (goer)
        = "sutra klama" (fast-goer = runner)
```

## Key Cmavo (Grammar Words)

| Cmavo | Function | GF(3) |
|-------|----------|-------|
| cu | selbri separator | 0 |
| lo | descriptor (veridical) | +1 |
| le | descriptor (described) | -1 |
| nu | event abstraction | 0 |
| ka | property abstraction | +1 |
| du'u | proposition abstraction | -1 |
| ja | logical OR | 0 |
| je | logical AND | 0 |
| jo | logical IFF | 0 |

## Resources

- [la sutysisku](https://la-lojban.github.io/sutysisku/) — dictionary
- [la vlasisku](https://vlasisku.lojban.org/) — search engine
- [CLL](https://lojban.org/publications/cll/cll_v1.1_xhtml-section-chunks/) — Complete Lojban Language
- [la karda](https://mw.lojban.org/papri/la_karda) — reference card

## Integration with IES

```julia
# Parse Lojban to ACSet
function lojban_to_acset(text::String)
    parse_tree = camxes_parse(text)  # PEG parser
    acset = BridiACSet()
    for bridi in parse_tree
        add_selbri!(acset, bridi.selbri)
        for (i, sumti) in enumerate(bridi.sumti)
            add_sumti!(acset, sumti, place=i)
        end
    end
    return acset
end
```

## Lojban ↔ String Diagram Morphism

The functor `L: Lojban → StringDiag` maps:
- selbri ↦ box with n input wires
- sumti ↦ wires
- tanru ↦ sequential composition
- connectives ↦ parallel composition (⊗)

This makes Lojban a **free monoidal category** generated by gismu.

---

*".i mi jimpe fi lo bangu"* — "I understand about language"


---

## 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.*