coulomb/clay-borg
4
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

CB-RES-0009: extensive form is the lingua franca
Some checks failed
ci / check (push) Failing after 4s
Details

Browse source 
Two questions from the maintainer — is there a game-theory mapping to
Ludii's language, and is that language formal enough to derive one from.
Yes, no, and the no does not matter.

The mapping is proven, not to be invented: "The Ludii Game Description
Language is Universal" shows the language can represent an equivalent game
for any finite, non-deterministic, imperfect-information game, extending
earlier work limited to finite deterministic fully-observable
extensive-form games. EFG is also OpenSpiel's object, so the same
formalism connects description to analysis: Ludii -> EFG <- OpenSpiel.

Ludii's syntax is formal and unusually so — a class grammar derived
automatically from its source. Its semantics are its Java: a ludeme means
what its class does, and Ludii effectively makes Java the game description
language. So there is no independent calculus to extract. The formality
lives in the universality RESULT, not in a definition of meaning. GDL has
the semantics and pays for it in speed — six times on Gomoku, twenty on
Amazons and Hex, over two hundred on Chess.

Conclusion: do not derive a language from Ludii; target the EFG directly.

And we are closer than the tracks assumed. The journal is the history,
Outcome is the payoff, legal_commands gives the actions — and
project(Viewer::Player(seat)) IS the information partition, built so a
player is not shown another's hand and unremarked as exactly the machinery
imperfect information needs.

Three gaps: chance is folded into a seed so a game is one realisation
rather than a game with chance nodes; perfect recall is unasserted, which
CFR and exploitability both assume; and commit/reveal is the standard EFG
encoding of simultaneity but is never stated as such. Perfect recall is
checkable from the journal today and is now Track B's first task — if it
fails, every equilibrium concept we might quote is unsound here.

Also re-vendored the catalog twice: ground-game added H2 — scoped problem
stress, applying End Stress by personal/bond/global scope instead of flat
to everyone, which is a direct response to our reading that H1's tax
scales with the Problems while its intended effect does not.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
This commit is contained in:
tegwick 2026-08-08 14:57:25 +02:00
parent 401b82bccc
commit 55a475b1a9
7 changed files with 301 additions and 15 deletions
Download patch file Download diff file Expand all files Collapse all files

18
simulators/README.md
View file

@ -49,7 +49,7 @@ owner · first release · licence · language (checked/unverified)
| profile | in one line | track |
|---|---|---|
| [`ludii.md`](ludii.md) | the closest relative: ludemes, breadth, speed | A |
| [`ludii.md`](ludii.md) | the closest relative: ludemes, breadth, speed — **syntax formal, semantics is its Java** | A |
| [`gdl-ggp.md`](gdl-ggp.md) | the academic ancestor; agent generality over designer support | A |
| [`rbg.md`](rbg.md) | regular boardgames — a speed-focused rival description language | A |
| [`ai-ai.md`](ai-ai.md) | **the closest relative for what we want to become**: GGP with designer-facing metrics | A, C |
@ -58,6 +58,22 @@ owner · first release · licence · language (checked/unverified)
| [`machinations.md`](machinations.md) | economy and feedback loops, diagrammatic | — |
| [`play-substrates.md`](play-substrates.md) | Tabletop Simulator, boardgame.io — play without analysis | — |
## The formal question, answered
**Is there a game-theory mapping to Ludii's language, and is that language
formal enough to derive one from?**
**Yes to the first, no to the second, and the second does not matter.**
Ludii's universality result grounds it in **finite, non-deterministic,
imperfect-information extensive-form games** — the same object OpenSpiel's
CFR and exploitability consume. Ludii's *grammar* is formal (derived from
its class hierarchy) but its *semantics are its Java*, so there is no
independent calculus to extract.
**Conclusion: target the extensive-form game directly, not a language
derived from Ludii.** Worked through in
[`../research/CB-RES-0009-extensive-form-is-the-lingua-franca.md`](../research/CB-RES-0009-extensive-form-is-the-lingua-franca.md).
## What this survey has already changed
**Ai Ai and Browne's criteria are the finding.** Track C was written in