What Lies Beneath: Statistical Structure in Voynichese Revealed by Transformers

[quimqu]

Well, that's the main question for me, because we already know about a lot of regularity from curve-line systems, slot grammars, etc. These approaches have explicit simple rules that are easy to analyze and compare, as opposed to black-box GPT models.

Without some metric that shows that a GPT based approach identifies structures beyond already identified with previous methods, it's hard for me to see if the GPT based approach is of any use at all.

I ran a validation test on a recent output of 891 generated words using a simplified slot grammar system adapted to EVA transliteration conventions.

Basic slot grammar rules:

valid_prefixes = ("qo", "ch", "sh")
valid_suffixes = ("y", "dy", "aiin", "ain", "daiin")
invalid_double_letters = ("tt", "pp", "ff")
invalid_final_glifs = ("q", "e", "ch")

Adapted for EVA transcription in Courier-like glifs:

valid_prefixes = ("4O", "S", "Z")
valid_suffixes = ("9", "89", "AM", "AN", "8AM")
invalid_final_glifs = ("4", "C", "S")
invalid_double_letters = ("PP", "BB", "FF")

Summary of results:

• ✅ 96.74% of the generated words match the slot grammar rules
  
• ✅ 95.5% of the total set correspond to real EVA words from the corpus
  
• ⚠️ 100% of the words have valid final glifs and no invalid double letters (so these two conditions have been learnt 100%)
  

Below is a list of the invented words that fulfill 100% the slot grammar restrictions:

Correct invented words: ['SCCX9', 'ZCCC9', '4OFAECC89', '4OFAEZC89', '4OFAEFCCC9', '4OFAEO9', 'SCCC89', '4OFAEZC89', 'SEFAN', '4ORAR9', '4OFCC889']

Below is a table of the invented words that do not fulfill 100% the slot grammar restrictions, and why:

Word	Prefix	Suffix	EndOK	NoBadDbl	✅ AllOK
ROPAJ	False	False	True	True	False
OFAEZE	False	False	True	True	False
AEOR	False	False	True	True	False
EZCC89R	False	False	True	True	False
4OESCC9R	True	False	True	True	False
ESCO8	False	False	True	True	False
4CFAR	False	False	True	True	False
8AROE	False	False	True	True	False
OEFCCC89	False	True	True	True	False
FAEOE9	False	True	True	True	False
POEZC89	False	True	True	True	False
EFS9	False	True	True	True	False
OZCC9	False	True	True	True	False
AEFM	False	False	True	True	False
2OEZCC9	False	True	True	True	False
OEFAROR	False	False	True	True	False
2OEZCC89	False	True	True	True	False
E8AN	False	True	True	True	False
Z2AE	True	False	True	True	False
AEAR	False	False	True	True	False
8EAM	False	True	True	True	False
RSCC89	False	True	True	True	False
8AEZC9	False	True	True	True	False
2AROE	False	False	True	True	False
EOEZC9	False	True	True	True	False
BOEFAN	False	True	True	True	False
EOEFCC89	False	True	True	True	False
4OFOEOE	True	False	True	True	False
4OFCCOE	True	False	True	True	False

The high percentage of conformity suggests that the generation process is strongly guided by structural constraints similar to those observed in actual Voynichese. While not all words match real entries from the manuscript, most invented forms remain within plausible morpho-phonological boundaries defined by the slot grammar. This supports the idea that the model is not producing random noise, but instead approximates a coherent internal system—whether artificial or natural.