GLTHR.com, by Guillaume Lethuillier

Essays and investigations into language and AI, the inner workings of old games, ciphers, puzzles, and software.

Selected work

Delimiters in LanguagesA universal duality in languages: the same symbols either act or are merely quoted, and delimiters mark the shift, from Homer’s formulas to string literals, DNA and large language models. 4 articles · 2024–2026

Experiments in Intelligence

Why XML Tags Are So Fundamental to ClaudeAnd What That Tells Us About Language Delimiters in Languages
Mar 1, 2026
Model Collapse and the Need for Human-Generated Training DataA Proposal for Certified Human-Written Training Data
Aug 5, 2025
Special Tokens: The Quotation Marks of LLMsWhat Happens When a Delimiter Shows Up in Plain Text Delimiters in Languages
Feb 22, 2025

Human & Agentic Languages

Adventures in Computation

Discovering Errors in Donald Knuth’s TAOCPTwo Reward Checks from the Bank of San Serriffe
Mar 8, 2025
Contextual Yet Non-Descriptive ErrorsProposal for Automatically Generated Error Codes
Oct 24, 2023
20 MonkeysGenerations of Virtual Monkeys Typing Hamlet
Oct 15, 2015
Theseus, Penepos, and the Eternal LabyrinthA Parable About P and NP
Jun 7, 2015

Digital Archeology

The Riven DiffsSeeing Riven (1997) Differently Riven (1997)
Jan 3, 2026
The Riven (1997) NavigatorA New Way to Explore the Original Riven Riven (1997)
Sep 20, 2025
The Myst Graph, 3: Creating the Graph Using DeMystify The Myst Graph
May 9, 2025
The Myst Graph, 2: Unreachable Views and Disabled Links The Myst Graph
Mar 29, 2025
The Myst Graph, 1: The 1993 Game as a Directed Graph The Myst Graph
Mar 29, 2025

The Amateur Cryptanalyst

The Puzzle Bench