Autocatalytic Grammar

Autocatalytic Grammars

Rules generate new rules during derivation. The grammar evolves while you generate text.

Output

Tip: Generate runs a full derivation from the start symbol and lets the grammar evolve as it fires.

Live Grammar

Format: Nonterminal -> production | production. Terminals in quotes, nonterminals bare.

Advanced Settings

Seed (blank = random)

Max Steps per Run

Autocatalysis Rate

Termination Damping

Start Symbol

Catalyst Target Nonterminals (comma)

Starter Grammar (Editable)

# Initial seed: minimal - will grow itself. S -> A B A -> "hunger" | "faith" | "silence" | "salt" | "prayer" B -> C | D C -> "descends" | "circles" | "abides" D -> "loosens" | "burns" | "returns"

Lexicon

river, stone, ember, light, shadow, vow, grain, breath, ash, ladder, mirror, gate, thread, hunger, faith, silence, salt, prayer, dusk, tongue, sleep, thunder, root, wing, seed, wheel, debt, chain, desert, psalm

Runtime Stats

lexicon: 0 rules: 0 firings: 0 spawned: 0 mutations: 0

Autocatalytic Grammars - How it works

Autocatalytic Grammars treat a context free grammar as a living system. As the text is derived, the rules that fire can synthesize new rules and graft them back into the grammar in real time.

Basic usage

• Generate builds a complete sentence or line starting from the start symbol (default S) and allows the grammar to mutate as it runs.
• Starter Grammar is editable. Change it and click Load Starter to reset the live grammar.
• Lexicon is the pool of words used when new rules are synthesized.
• Runtime Stats show how many rules you have, how often they fire, and how many new ones have been spawned.

Autocatalytic loop

• Firing: The engine rewrites the leftmost nonterminal with one of its productions.
• Catalysis: With probability set by Autocatalysis Rate, the fired rule creates a new production.
• Grafting: The new production is inserted into a target nonterminal, immediately changing the grammar.
• Damping: As steps accumulate, the engine slowly prefers more terminal heavy productions to help runs terminate.

Parameters

• Seed: Fix this for reproducible runs. Leave blank for fresh randomness.
• Max Steps per Run: Upper bound on how many derivation steps a single Generate call may take.
• Autocatalysis Rate: Higher values mean more new rules and faster drift in the grammar.
• Termination Damping: Higher values bias the system toward stopping sooner.
• Targets: A comma separated list of nonterminals that will receive most of the new productions.

Exporting to RPG

Use the Export Grammar button to open a popup containing the current grammar in RPG style (LHS -> RHS | RHS). You can copy that text and paste it directly into your Recursive Production Grammar (RPG) engine.

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Exported Grammar (RPG Format)

Copy this context free grammar directly into your Recursive Production Grammar (RPG) engine.

Open RPG (Schrodinger Poetry)