Physical Symbol System Demo

This toy production system manipulates symbols with simple rewrite rules to reach a goal state.

What to do: Type a short sequence of letters into the Start field (e.g., ABC) and a rearranged version into the Goal field (e.g., CAB). Click Solve and watch the system find a step-by-step path using breadth-first search. Try different start and goal strings.

Think about: The system follows formal rewrite rules — swapping and rotating symbols — with no understanding of what the symbols mean. Does that count as intelligent behaviour? Compare with Newell and Simon's Physical Symbol System hypothesis and Searle's Chinese Room objection.

Rules
1. Swap adjacent symbols (e.g., AB -> BA)
2. Rotate left (ABC -> BCA)
3. Rotate right (ABC -> CAB)
Solution (breadth-first search, max depth 6)