Every class of elementary cellular automaton, described using only the crop-glyph vocabulary. Two classes that end up wearing the same word are a gap — a distinction the language cannot make, with the two pictures attached.
The lexicon reads a mark stamped into a field. A rule is not a mark, so something had to decide what the mark is. The choice here — and it is a choice, the only place judgment lives — is that the glyph is the space-time raster the rule stamps: one cell struck at the top, and whatever grows below it. Seven marks were given a measurement:
| Lexicon mark | What it does | Measured as |
|---|---|---|
| Filled disc / thin ring | mass vs path | long-run ink on the page |
| Dots on a ring | quantised steps, a clock | cycle length on a 24-cell ring |
| Saw-tooth ring | the ratchet, directed time | reversibility, checked exhaustively |
| Open arc / non-closure | handedness from a closure defect | does the rule equal its own mirror |
| Concentric rings | depth / iteration levels | self-similarity at half scale |
| Radial spokes | broadcast from a source | how far one struck cell travels |
| Tangency / penetration | optional door vs alters the core | damage from touching one cell |
Each block below is a set of classes the lexicon calls by the same name. Left picture: one cell struck. Right picture: a random field. If the pictures look different to your eye and the language calls them the same, that is a missing mark.
Gold border = the class contains both a filled and a thin reading, so the mirror/complement collapse is throwing away a distinction the lexicon treats as two different currencies.
A language can only be scored on what the test can exercise. Five marks in the lexicon describe relations a one-dimensional ring has no room for — a centre, a rim, a body inside a body. Their absence here is a limit of the test, not a verdict on the mark.