Structure and Structural Views (STRUCT-CAL)
About this pattern
This is a generated FPF pattern page projected from the published FPF source. It is canonical FPF content for this ID; it is not a FPF Reference product feature page.
How to use this pattern
Read the ID, status, type, and normativity first. Use the content for exact wording, the relations for adjacent concepts, and citations to keep active work grounded without pasting the whole specification.
Type: Architectural pattern Status: Stable Normativity: Normative unless explicitly marked informative
Use this pattern when a practitioner needs to select U.Structure as the EntityOfConcern: an organization among exact constituents and obtaining relations, selected to expose a relation class, applied constraint, invariant, variation class, preserved arrangement, or lost arrangement that changes the next engineering or reasoning action.
Relations
C.30.TFSContent
Problem frame
Use this pattern when a practitioner needs to select U.Structure as the EntityOfConcern: an organization among exact constituents and obtaining relations, selected to expose a relation class, applied constraint, invariant, variation class, preserved arrangement, or lost arrangement that changes the next engineering or reasoning action.
The first A.22 question is not “which diagram or record shows the structure?” It is “which organization is selected for this named use?” Recover that organization in this order:
- identify every constituent independently through the content that defines its kind and identity;
- recover the exact relation occurrences among those constituents that actually obtain under their direct predicates;
- state the exact constraints applied to those constituents and relations, plus the named selection-use frame that says what question or action this organization serves;
- name the resulting selected organization and the admissible action or stop that follows.
When the use makes a load-bearing claim that a structure was selected, also recover the selecting system, its dated selection work and exact method-enactment relation, and the exact participant relations or A.6.1 bindings used by that work. Those neighboring facts support the selection judgment; they do not enter U.Structure identity. If the judgment must persist, identify a separate C.2.1 result episteme whose claim content designates the selected structure.
The first useful move is small:
StructureQuestionCard@Project is a project-side triage aid for this selected-structure use. It is not a new structure kind. Fill the reliance row only when extraction, coarsening, source-description, base-dependence, grounding, evidence, lens, simulation, representation, or action reliance is being claimed; otherwise leave it unused and keep the move on selected structure.
Here @Project is a compatibility and retrieval cue, not a type or relation assertion. It identifies neither a project entity nor a composite project U.Work, and it establishes no context, authority, viewpoint, or parthood. When this card is used in relation to one actual project, name that exact composite U.Work and the relation by which the current structure-selection work, decision, description, or other identified object concerns it. Otherwise no project-work reference is implied. The same rule applies to ArchitectureStructureKindTriage@Project below.
Stop at this card when it makes the next structure use clear. Open heavier records only when a named description, view, publication, extraction, coarsening, comparison, mathematical-lens, architecture-description, or other neighboring claim is being made.
What goes wrong if A.22 is missed: the practitioner reasons from the visible diagram, source publication, source-use record, lens output, generated representation, project record, or architecture description instead of asking which organization is selected and what loss or reliance boundary matters for action.
What A.22 buys in practice: a practitioner can name selected structure, state preserved and lost structure, name source-basis or lens reliance only when it is being claimed, add a StructureUseReturnCondition when loss matters, and apply the FPF definition or test for any non-structure claim being made.
Not this pattern when the question under repair is grounded architecture adequacy, architecture structural-view adequacy, or mathematical-lens use. Use [C.30](/generated/patterns/C.30), [C.30.ASV](/generated/patterns/C.30.ASV), or [C.29](/generated/patterns/C.29) respectively. For any other claim, use the pattern that defines or tests that claim and keep A.22 only to the selected-structure portion.
Thin precision-restoration pointer: when the wording still may name a structure, a structure description, an architecture description, a view, a publication form, or another exact claim, use [C.30.P](/generated/patterns/C.30.P) or [C.30.STRAT](/generated/patterns/C.30.STRAT) first as triggered. Apply A.22 only after the selected-structure claim or structure-view portion is recoverable.
Problem
FPF needs a selected-structure EntityOfConcern that is usable across domain ontologies, mathematical formalisms, architecture notations, and publication forms. Working projects often notice that "the structure" is doing real work:
- dependencies repeat across cases;
- a method or work description hides an invariant relation;
- a model compresses a trace by preserving one relation class and losing others;
- a diagram shows an arrangement but is mistaken for the arrangement itself;
- a mathematical lens exposes preserved structure but is then overread as ontology;
- an architecture discussion needs selected structure over a holon before it can describe architecture.
How can FPF let a practitioner name structure as an EntityOfConcern while preserving the distinction between:
- selected structure and the source-description relation, source-use relation, evidence relation, lens output, simulation, generated representation, or declared substrate from which it was inferred or declared;
- structure and a Description episteme or view of that structure;
- structure and a publication face, diagram, table, graph, or publication form;
- structure and mathematical-lens application;
- structure and another FPF claim kind whose definition or test remains in the cited pattern;
- structure in general and architecture-specific structure selected by
C.30.
Forces
Solution
Select U.Structure as the A.22 ontic head: a dependent, non-agentive organization selected from independently identified constituents and exact obtaining relation occurrences under applied constraints for one named use frame.
The constituents keep their own identities and kinds. Every selected relation occurrence must already satisfy its defining predicate and retain identity under that predicate's occurrence rule. A system or practitioner selects their organization; A.22 supplies the identity and boundary rule for that selected organization.
The applied constraints are the exact constraint claims used in the selection judgment, not the identity of the document, table, rule card, or constraint episteme that carries them. A usable frame states the question, admissible action, and stop or return condition. A generic phrase such as “current use” or “appropriate structure” is not a use frame. Any optional explanatory overread follows F.19:4's plausible-reader test and remains outside structure identity.
A system may perform dated structure-selection work by an exact method and may create a result episteme about the selected structure. Recover that basis when a load-bearing selection claim is current. The method, work, A.6.1 binding or direct participation relation, decision, and C.2.1 result episteme are neighboring objects outside structure identity.
A diagram, graph, table, model, description, view, or publication may designate, represent, or describe the selected organization and its already identified constituents. Use C.29, C.2.1, E.17.0, and the exact publication or source-use patterns for those neighboring claims; the direct participant and relation predicates remain the obtaining basis.
Base U.Structure Identity and Selection
For a selected structure S, recover four identity discriminators:
Base U.Structure identity has no ambient context field. A bounded-context label, U.ContextSlice, U.ClaimScope, project record, description, view, graph, table, or publication is not automatically an additional discriminator. If an exact scope is referenced by an applied constraint, that constraint contributes through the third discriminator. If a model-use structure is independently selected as a constituent of another structure, it contributes through the first discriminator.
The first discriminator is an exact plurality, not a graph node set created by notation. A separately useful C.13 collection may designate the same constituents, but collection membership neither proves parthood nor replaces their direct identities. The second discriminator contains the exact relation occurrences chosen for this organization; a relation name, edge label, tuple position, or adjacency row is insufficient. The third contains the semantic constraints actually applied; changing only the rationale, formatting, or publication of an unchanged constraint claim does not change this discriminator. The fourth names the use question, admissible action, and stop or return condition.
Two references resolve to the same U.Structure when all four discriminators resolve to the same values. A changed designator, selecting system, method, work occurrence, result episteme, description, graph, representation scheme, view, or publication leaves the structure unchanged when the four discriminators remain unchanged. Replacing a constituent, a selected relation occurrence, an applied constraint, or the named use frame can identify another structure. If a relation occurrence itself may have been reidentified, apply its direct relation pattern before reapplying A.22. A change to an explanatory guard alone does not change identity. If its content changes an applied constraint or a frame value, compare that existing discriminator.
If no current predicate definition, applicability condition, or occurrence rule can identify the required constituent or test the obtaining-relation claim for this use, stop at the exact description or representation and return missing-governor. If the governor exists and the available case basis is sufficient to apply its positive test but that test fails, return factually unsupported; if a fact needed to decide the test is unavailable, return missing-information. State a negative only when an applicable non-obtaining criterion or complete closure basis and satisfying facts establish it. If the constraints or named use frame are absent, name that exact gap: the material may show an arrangement, but it does not yet support the claimed selected U.Structure.
The following two compact records are recovery aids, not new ontic kinds. In SelectedStructureBasis, the selected structure, constituents, selected obtaining relations, applied constraints, and use frame state identity; the preserved/lost and action/stop rows state the use-return boundary rather than adding identity fields.
StructureSelectionUse records how a system performed the selection and reached the judgment. SelectedStructureBasis records the four identity discriminators plus the use-return boundary. Do not copy the system, work, method, result episteme, or decision into the structure basis. A U.ClaimScope, effective U.ReferenceScheme, or model-use structure that merely qualifies a claim about either record does not enter base identity. A scope referenced by an applied constraint or a model-use structure selected as a constituent enters only through that already declared discriminator. stopOrReturnCondition is another name for stopOrNonAdmissibleUse, not an independently filled value.
A.22 structure-aspect names such as functional, mereological, modular, transformation-flow, control, semantic, causal, dynamical, algebraic, topological, geometric, or coarse-grained remain cues for which relations and constraints to recover. They do not identify a structure without the four discriminators. C.30.ASV ArchitectureStructureKindRef values remain architecture-local classifiers; a matching label does not imply identity.
Compact auxiliary boundary
Use description, publication, source-use, evidence, work, gate, decision, release, architecture-description, and mathematical-lens patterns when those claims are being made. The A.22 application contains the selected-structure portion and the structure-use return condition that protects that structure use; use each neighboring pattern only for the definition or test it contributes. A publication, diagram, graph, table, dashboard, file, model card, generated representation, or lens output may make a structural description or view available; it does not become the selected structure or supply neighboring claim authority by appearance.
Constraint-governed unfolding structure
Use A.22.CGUS when the current A.22 structure has several locally declared loci whose bindings identify the independently selected constituents for the unfolding question, and when the selected obtaining relation occurrences together with the applied constraint claims define at least two potential continuations across allowed cases. The loci are not free-standing A.6.5 slots. A separate case- and time-indexed result may enable zero, one, or several candidates. This specialization remains U.Structure; it is not a route, workflow, method, work plan, performed work, decision, evidence relation, gate, architecture description, or publication.
Use A.22.CGUS only when the candidate has several loci and cross-locus constraints. A route card, table, graph, README entry, narrative, slide, or happy-path example may describe or demonstrate the unfolding structure, but it is not the structure itself.
Bounded And Cross-Context Model-Use Structure Specializations
BoundedModelUseStructure is a U.Structure selected over one exact model episteme, exact admitted model-use holons, the obtaining model-applicability, actual model-use, and model-expression-coherence occurrences defined and tested by A.1.1, exact applied constraint claims used by the selection judgment, and one named bounded-model-use frame. Its A.22 identity uses exactly those constituents, selected occurrences, exact constraint claims, and frame. A claim scope, membership outcome, boundary display, or carrier is not an applied constraint by itself; a constraint claim may instead state a proposition about that scope or its A.2.6 membership predicate. No boundary crossing participates in that identity. Continuity across model editions additionally requires the exact C.2.1 episteme-edition relation and declared A.1.1 continuity rule. It is not a holon, description, view, or endpoint manufactured by a later crossing.
CrossContextRelationStructure is a conditional specialization of a different already identified U.Structure. Membership requires exact obtaining crossing occurrences that satisfy independently defined predicates, selected among several bounded model-use structures, applied constraints, and one named crossing-analysis use, with all four A.22 base discriminators established. Until a compatible crossing predicate and current facts establish those occurrences, a Context Map can describe only a proposed crossing organization and no positive CrossContextRelationStructure member is asserted. The selecting system and its work remain separate. Sharing a participant does not merge structures, and overlap does not prove parthood.
Pending local name settlement. The following F.18 NameCard is local to A.22 while the positive crossing-occurrence basis is unavailable. It does not create the structures, crossing relations, mapping method, or view.
This pending card has no UnifiedTermRowRef. Until its refresh condition is met, CrossContextRelationStructure is an A.22-local provisional designator only; other Core hosts must cite the descriptive A.22 conditional cross-structure rule rather than consume that label as public vocabulary.
DDD Context Mapping names a repeatable U.Method. A.15.2 defines the intended mapping plan. For each exact dated mapping Work individual, use A.13 to identify the actual performer and let A.15.1 independently admit the Work from its history, enacted Method, extent, and containing-System relation. If the mapping account must also identify the assignment under which the Work was performed, check that relation separately through F.6; F.6 identifies neither assignment nor performer. C.2.1 independently identifies the candidate episteme called a Context Map. While exact independently defined crossing occurrences or the four A.22 base discriminators are missing, its EntityOfConcern is the proposed or described crossing organization, not an exact CrossContextRelationStructure. Only after both conditions are met may a corresponding C.2.1 episteme designate the exact structure. Either episteme is additionally a U.View only when the E.17.0 test establishes EpistemeViewpointConformanceRelation(E, P). Use C.29 for any representation relation and E.17/E.24.PUB for rendering or publication; form and carrier remain separate. Thus Method, plan, Work, performer, optional assignment check, proposal, selected structure, candidate episteme, dependent view membership, representation, and publication stay distinct while the external source terms remain retrievable.
Transformation-flow structure network profile
Use E.18.NET when one engineering use selects two or more independently identified transformation-flow structures, or nested networks of them, together with exact obtaining relations across their boundaries. Apply the four A.22 discriminators directly: the exact TFS or nested-network members are the constituents; the exact cross-member relation occurrences satisfy their defining predicates and identity rules; the exact applied endpoint, boundary-exposure, and acyclic direct-member constraints are selected under E.18.NET; and the named network-use frame states the practical question, admissible action, and stop or return condition. Any optional explanatory overread follows F.19:4 and remains outside structure identity. The return condition reopens selection when a member, relation, constraint, or use-frame value changes and is not a fifth identity discriminator. The result is one dependent, non-agentive U.Structure specialization. E.18.NET defines the network's detailed identity, reference, recursion, local-state, and conformance rules; A.22 does not copy those fields.
Use the first discriminator to record structure constituents. Introduce a separately re-identifiable world-side membership relation only when a receiving use needs it and can supply its participants, obtaining predicate, and identity rule.
Structure claim reliance relation selection
When a structure claim relies on something beyond the selected structure itself, choose the reliance relation kind, name the relation record by value, and name the definition or test used for that relation. Use that definition for the relation's required fields and use limits.
If no reliance relation kind can be selected, keep the wording as a source-finding note, recognition cue, ordinary help, quote-only wording, or reduced-use cue. Do not create a generic reliance record to make the claim look resolved.
U.Structure does not carry description, representation, extraction, mathematical-lens, simulation, or generic reliance state as an internal structure field. Those are source-description, source-use, base-dependence, evidence, lens, extraction, simulation, or publication relations about a structure. PublicationRef is not an admissible substitute for the source episteme, source view, evidence relation, SWBD, or lens output.
Structural descriptions and views
Structural descriptions and views reuse existing episteme and view machinery. Architecture does not define a second ontology of descriptions, views, viewpoint bundles, multi-view descriptions, publications, publication forms, or source-pin sets. Every record whose name ends in Description@Context here designates an existing U.Episteme: C.2.1 supplies its identity and E.10.D2 constrains its describing use. Every record whose name ends in View@Context remains that same episteme and has U.View membership only when the E.17.0 conformance test to an exact viewpoint episteme passes. A.6.3 supplies only an optional source-to-receiving construction. The @Context suffix is a local retrieval convention; it does not add a context object or identity field.
In the description and view forms below, admissibleUse states the actual use and its limits. nonAdmissibleUse?, also named groundedNonAdmissibleUse?, carries one optional explanatory guard under F.19:4's plausible-reader test; the two names do not introduce separate fields.
The exact EntityOfConcern and effective scheme identify the episteme with its claim content under C.2.1. selectedViewpointRef, when present, records that this named describing use selects exact viewpoint P; it does not establish conformance or U.View membership. selectedModelUseStructureRef, when present, resolves one independently selected BoundedModelUseStructure used by the receiving assertion or calculation; it is neither episteme identity nor another viewpoint field. When reliance is on a named claim, U.EpistemeRef resolves the exact C.2.1 claim-bearing episteme; a PatternID normally locates the definition, constraint, or test it uses, and an exact ClaimGraph is added only when that identity changes the use.
Extracted and transformed structural views
Use extracted or transformed structure records when a view of structure is obtained from a corpus, trace, model, simulation, or generated representation, through a mathematical lens or coarsening pass, or within an observer or budget boundary, and may hide distinctions.
Structure-use return
StructureUseReturnCondition is present when compression, extraction, coarsening, evidence reuse, mathematical-lens use, simulation, ML evaluation, bounded exception, many-to-many allocation, or decision reliance hides a distinction needed for action, assurance, causal use, legal review, regulatory review, comparison, or subsequent decision reopening.
Do not make structure-use return mandatory for ordinary local recognition when no hidden distinction is being used for action. The condition is needed only when the repaired text still relies on a hidden selected-structure, source-basis, source-description, evidence, lens, simulation, extraction, or representation distinction.
Relation to architecture
StructuralAspectDescription@Context describes one selected structural aspect under A.22. It is not an ArchitectureStructureKindRef by itself. ArchitectureStructuralView@Context is a C.30.ASV view over structures selected by ArchitectureOf@Context and typed by ArchitectureStructureKindRef.
A.22 is intentionally upstream of C.30. Architecture uses structure; structure does not import architecture as a parent.
C.30 uses A.22 by selecting architecture-relevant structures for one described holon through ArchitectureOf@Context. C.30.ASV then defines and tests architecture structural views over those selected structures. A structure can be used by architecture, but a structure is not an architecture merely because an architecture description refers to it.
Architecture-related terms governed by C.30 or its subpatterns include ArchitectureOf@Context, ArchitectureDescription@Context, ArchitectureStructuralView@Context, ArchitectureStructureKindRef, ArchitectureStructureKindTriage@Project, FunctionalStructureView@Context, ArchitectureTransformationFlowStructureRelation@Context, ControlStructureView@Context, and CrossScopeArchitectureResidualTriage@Context. A.22 may name them as FPF pattern applications. It does not define their architecture-specific conformance.
Boundary and repair table
Worked slices
Maintenance-isolation structure selection. A planner needs to choose which relations matter when isolating a pump skid for maintenance.
Pump37_MaintenanceIsolationStructure is identified by the exact constituents, exact selected obtaining occurrences, applied isolation constraints, and maintenance-isolation use frame. SelectionWork_2026-07-25, the enacted method, and any C.2.1 episteme that records the judgment remain separate. A C.29 graph may represent the same organization, while the direct predicates of the selected relation occurrences remain its obtaining basis. A visually identical graph with an unestablished connection remains a representation candidate.
Architecture kernel slice. A team says, "the architecture is the graph." Recover the selected structure and the graph's exact reliance relation:
The practitioner can now use the graph through the selected source-description, base-dependence, evidence, or lens relation and route the architecture claim to C.30.TFS-REL.
Extracted code structure slice. A code-agent relation graph or probe JSON reports imports, calls, registry wiring, and data-flow links. A.22 treats it as an extracted structural view only when the source codebase or publication, extraction method, preserved structure, lost structure, validation boundary, and structure-use return condition are named. Its admitted use is the declared extraction result. When the intended use is a claim about the codebase architecture, internal agent belief, assurance, or release readiness, recover that claim's own evidence and governing predicate.
Archetypal Grounding
Bias-Annotation
Bias lenses: Arch, Onto, Epist, Prag, Did, Gov. Scope: universal within FPF structure claims.
This checklist verifies the preceding guidance after the practitioner has chosen the selected repair action; it is not a required project control form and not a substitute for the card, note, view, relation, or repair guidance above.
Conformance Checklist
Common Anti-Patterns and How to Avoid Them
Consequences
Rationale
FPF needs one general selected-structure kind because many useful claims depend on organization before they depend on a specific architecture, mathematical, measurement, or publication pattern. The selected structure is dependent and non-agentive. Claims about it are carried by separate epistemes and views: it can be described, sourced, compared, coarsened, extracted, or used by architecture.
The selected design keeps A.22 small enough for first use. A practitioner can write one StructureQuestionCard@Project and stop. Heavier describing-use viewpoint selection, independently selected model-use structure, A.6.6 base-dependence, extraction, lens, evidence, and structure-use return records are used only when the next use would otherwise hide loss, source-basis dependence, or a non-structure claim kind.
The reason to keep C.30 separate is architectural clarity. Architecture is selected structure for an exact described holon and architecture concern; architecture descriptions are Description epistemes and specification-use cases or views over that claim, while publications only make those epistemes or views available. A.22 supplies the structure substrate, not the architecture ontology.
SoTA-Echoing
Relations
Builds on: A.1, C.13, C.2.1, A.6.REL, A.6.0, A.6.5, A.3.1, A.6.1, A.15.1, A.6.P, A.7, A.6.2, A.6.3, A.14, C.16, C.29, E.10.D2, E.10, C.2.P, E.17.0, E.17.1, E.24, E.24.PUB, and F.18.
Coordinates with: A.1.1, A.2.6, A.22.CGUS, C.30.P, C.30.STRAT, C.30, C.30.ASV, C.30.TFS-REL, C.30.LCA, C.30.ILC, A.6.F, E.18, E.18.NET, E.18.3, A.10, G.6, B.3, A.20, A.21, C.28, A.15, C.11, C.16, C.25, G.5, C.33, C.34, and C.35 when architecture-specific structure-capture, preservation, or discovery adequacy claim kinds are being made.
Architecture-specific adequacy: C.33, C.34, and C.35 define or test architecture-specific capture, preservation, and discovery adequacy over selected structures. A.22 keeps the general selected-structure portion; it does not decide architecture use, candidate admission, measurement, evidence, assurance, or decision authority for those adequacy claims.
Does not replace: C.30.P or C.30.STRAT wording-use precision restoration, C.30 for grounded architecture adequacy and conditional architecture-description use, C.29 for mathematical-lens use, C.16 for measurement and characterization, C.28 for causal-use relation, B.3 for assurance, A.10 for claim-bound evidence reliance, G.6 for citable evidence-provenance paths, A.20 for internal-constraint validity, A.21 for gate decisions, the subject pattern for release claims, A.15 for work-family objects, C.11 for decisions, E.17 for a source-backed reader face, or E.24.PUB for publication occurrence, form, carrier, audience, bounded use, and availability.
Use F.19 for ordinary precise-plain-language repair and its plausible-reader test for optional guards; unresolved structure or architecture wording follows C.30.P or C.30.STRAT.
A.22:End
Last Updated: 2026-09-10 — upstream FPF commit a87d0ef4 (github.com/ailev/FPF)