FPF strict-distinction, selected-structure, architecture-description, and view apparatus (A.7, A.22, C.30.AD, E.17) | A description or view can expose one selected TFS or network without becoming that structure or evidence. | The mathematical description names exactly one subject branch, expression, preserved/lost structure, declared use, and boundary stop. | A readable model can guide inspection without authorizing action. | The selected E.18 TFS or E.18.NET network, publication face, evidence relation, or architecture claim changes. |
| SysML v2 — deliberately excluded | No move or lineage is adopted for E.18.2: SysML v2’s long-promoted model-and-diagram program is not treated as current working SoTA for this problem. | Search prominence, diagram familiarity, and the word system do not establish a useful structure/description boundary. | Use practices that solve the current modeling problem in operating tools and projects; do not import a SysML v2 basis by default. | Reconsider only on concrete project evidence that changes the current problem and outperforms the adopted working line. |
Applied category theory, wiring diagrams, and graph rewriting (Fong & Spivak, arXiv 1803.05316; Spivak, arXiv 1305.0297; Baez & Fong, arXiv 1504.05625; Bonchi et al., arXiv 1602.06771; Patterson/Spivak/Vagner, arXiv 2101.12046). | Formal expression is useful because it preserves some structure and drops other structure. | Quotient, fold, refinement, factorization, and wiring claims name what survives and what is lost. | Coarser and finer descriptions can be compared without pretending they are identical. | The preserved/lost structure, mapping mode, or C.29 lens-use adequacy changes. |
Digital-thread, research-object, and source-reference practice (RO-Crate paper, arXiv 2108.06503; Di Cosmo/Gruenpeter/Zacchiroli, arXiv 2001.08647; ISO 23247 digital-twin lineage). | Replay works only when record kinds remain distinct. | E.18.2 descriptions cite one E.18 TFS or E.18.NET network and exact related records rather than absorbing work, evidence, gate, and publication claims. | A trace graph can remain useful without becoming proof, plan, or performed work. | Source-currentness relation, work-family law, evidence, gate, or publication-use relation changes. |
| Engineering architecture practice uses functional, dataflow, and interface diagrams under explicit view, viewpoint, and correspondence discipline. | A diagram may describe architecture, transformation-flow structure, method, mechanism, or publication face according to the current EoC. | E.18.2 keeps only the mathematical-description relation; architecture adequacy remains under C.30, architecture structural-view adequacy remains under C.30.ASV, and reusable-structure characteristics remain under C.31. | Functional and dataflow diagrams can be used without semio-bias or architecture overclaim. | The architecture selected structure, viewpoint, or correspondence relation changes. |