"book-pflow-xyz/chapters/appendix-d-glossary.md" . . "Two distinct boundaries that older material treated as one. The *algebraic* boundary ($\\rho$) lies inside $C$ and separates transitions the tropical eigenvalue and uniform R1CS can handle from those they cannot; it does not affect composition. The *contextual* boundary (read/inhibitor arcs) lies outside $C$ and breaks free composition; it does not affect $\\rho$. Canonical statement in Appendix E."@en . . "Core–observer boundary"@en .