#A.19.SOURCE-SET-SPACE-SUBSTRATE:4 - Solution

Preface node heading:a-19-source-set-space-substrate-4-solution:24407

#What this page is

This is generated FPF reference text from the specification preface or supporting sections. It helps interpret FPF; it is not FPF Reference product documentation.

#Methodology

Use it to understand how the specification wants to be read, then return to a route, pattern, or work packet for active work. Cite generated IDs only when the wording changes the task decision.

#Content

Declare the source-set or search/outcome-space line through one explicit substrate stack, keep only the load-bearing core mandatory, and place every heavier requirement in conditional fields, interpretive qualifiers, or companion declarations.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.1 - Declared relation-and-ref-position stack and outside work

Use this pattern to declare only the substrate stack below:

• the declared source set that the line is acting on;
• the recoverable concrete source-set identity when the family name alone would be ambiguous;
• the search-side reference to one declared A.19 CharacteristicSpace;
• the outcome-side reference to one declared A.19 CharacteristicSpace;
• the explicit SpaceRefRelationKind over those two ref positions;
• the explicit source-to-outcome relation;
• and the explicit distortion, uncertainty, or error posture for that relation.

Do not use this pattern to declare:

• A.19 space typing itself;
• selector outcome publication, shortlist identity, or shipping closure;
• live pool policy or enactment planning;
• or optional interpretive-view families that interpret or reorganize an already-declared substrate.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.2 - Minimal declaration stack

Use the following notation-independent stack:

SourceSetSpaceSubstrate := <
  SourceSetFamily,
  SourceSetRef?,
  SearchSpaceRef,
  OutcomeSpaceRef,
  SpaceRefRelationKind,
  SourceToOutcomeRelation,
  DistortionPosture,
  SourceSetComposition?,
  DerivedViewKind?,
  BasePaletteRef?,
  OutcomeMapRef?,
  SpaceMetricRef?,
  TransitionRelationRef?,
  BridgeDistortionNote?
>

Interpret the fields as follows:

• SourceSetFamily names the primary declared source-set family that the line is anchored on.
• SourceSetRef? names the concrete declared source set or declared set result when several same-family source sets or set results are live or when one neighboring governing pattern must be cited to keep that identity unique. It may be omitted only when the concrete source set is unambiguous from the declared line.
• SearchSpaceRef points to one declared [A.19](/generated/patterns/A.19) CharacteristicSpace in the search-side position.
• OutcomeSpaceRef points to one declared [A.19](/generated/patterns/A.19) CharacteristicSpace in the outcome-side position.
• SpaceRefRelationKind states how those two refs relate. In ordinary use, the token is either sameDeclaredSpaceAs or distinctDeclaredSpaceFrom.
• SourceToOutcomeRelation is one controlled declaration slot. State at least direction, mode, and carrier.
• DistortionPosture is one controlled declaration slot with one primary posture token plus optional clarifying note. In this slice, lawful posture tokens include transparent-for-current-use, lossy-bridge, metric/model-dependent, transition-dependent, uncertainty-bearing, learned/adaptive, and unstable-under-refresh.
• SourceSetComposition, DerivedViewKind, and related ...Kind values remain declaration fields or controlled field values unless some governing pattern explicitly promotes them; they are not automatically independent heads merely because their names end with Kind.

This is an [A.6.5](/generated/patterns/A.6.5) / [A.6.P](/generated/patterns/A.6.P) move: SearchSpaceRef and OutcomeSpaceRef are ref-typed slot contents, while SpaceRefRelationKind is the explicit RelationKind token that governs how those two ref positions are read together.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.3 - Substrate declaration laws (SS-0..SS-7)

SS-0 - One substrate line, one explicit stack. Treat a line as declared substrate only if one recoverable source-set basis, two recoverable space refs, one explicit ref-to-ref relation kind, one explicit source-to-outcome relation, and one explicit posture are present together.

SS-1 - Ref typing is preserved. SearchSpaceRef and OutcomeSpaceRef must resolve to declared A.19 CharacteristicSpace. They do not become parallel space kinds, slot aliases, or role claims.

SS-2 - Source-set recoverability is mandatory. The reader must be able to recover not only the source-set family but, when several same-family source sets or set results are simultaneously live, the concrete declared source set or set result through SourceSetRef? or one cited neighboring governing pattern that uniquely identifies it.

SS-3 - Relation requirement must be explicit. SourceToOutcomeRelation is conforming only when direction, mode, and carrier are explicit enough to tell what is related to what, through which carrier/relation mode, and through which declared interpretive qualifier.

SS-4 - Posture honesty is mandatory. DistortionPosture must say whether the line is transparent for current use or qualified by loss, metric/model dependence, transition dependence, uncertainty, learning/adaptation, or instability under refresh. The line may not hide qualification in atmospheric prose.

SS-5 - Conditional and qualifier fields stay subordinate. SourceSetComposition, DerivedViewKind, BasePaletteRef, OutcomeMapRef, SpaceMetricRef, TransitionRelationRef, and BridgeDistortionNote may clarify the substrate, but they do not replace the core stack and do not become mandatory everywhere.

SS-6 - Publication and policy stay outside. Publication metadata, shortlist identity, live-pool policy, and enactment policy remain neighboring decisions. A substrate line may feed them, but it does not decide them.

SS-7 - Admission is fail-closed. If the source set cannot be recovered, either space ref is unresolved, SpaceRefRelationKind cannot be chosen honestly, relation direction, mode, or carrier remains vague, or posture remains unclassified, then the line is not yet a declared substrate. Keep it as a working gloss or move it to the governing pattern that can close the missing requirement.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.4 - Profiles

Use one of these ordinary profiles:

• Shared-space profile. SearchSpaceRef and OutcomeSpaceRef both resolve to the same declared CharacteristicSpace, and SpaceRefRelationKind = sameDeclaredSpaceAs.
• Cross-space profile. SearchSpaceRef and OutcomeSpaceRef resolve to two distinct declared CharacteristicSpace declarations, and SpaceRefRelationKind = distinctDeclaredSpaceFrom.
• Derived-source supplement. If the visible source set is one derived tradition, front, or palette view, keep DerivedViewKind and BasePaletteRef explicit so the derived view does not silently become the default meaning of the base palette or source set.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.5 - Operational declaration sequence (fail-closed)

When declaring one substrate-bearing line, proceed in this order:

0. Entry test. Confirm that the line really needs source-set plus search/outcome-space plus relation/posture discipline. If it only needs CharacteristicSpace typing, use A.19. If it only needs publication or policy, apply the governing pattern that carries that publication or policy question.
1. Recover the active source set. State SourceSetFamily. If several same-family source sets or set results are simultaneously live, fill SourceSetRef? or cite the neighboring governing pattern that makes that identity unique.
2. Recover the space refs. Point SearchSpaceRef and OutcomeSpaceRef to already-declared CharacteristicSpace.
3. Choose the ref-to-ref relation kind. Declare sameDeclaredSpaceAs only when both refs truly resolve to one declared space. Declare distinctDeclaredSpaceFrom only when they truly resolve to two distinct declared spaces. Do not leave this to reader inference.
4. State the source-to-outcome relation. Give direction, mode, and carrier explicitly. If one named OutcomeMapRef or another declared interpretive qualifier carries the relation, cite that qualifier explicitly. If not, state the carrier directly in prose.
5. State the posture. Declare whether the line is transparent for current use or qualified by loss, metric/model dependence, transition dependence, uncertainty, learning/adaptation, or instability under refresh.
6. Add only the fields that are really doing work. Add composition, derived-view, base-palette, metric, transition, or bridge qualifiers only when the current case actually depends on them.
7. Run the boundary check. If the line starts deciding publication metadata, shortlist identity, live candidate policy, enactment policy, or interpretive-view organization, stop and apply the pattern that governs that question.

Fail-closed rule. Do not treat the line as declared substrate if any of steps 1-5 remains unresolved. Incomplete recovery is a real defect here, not one stylistic omission.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.6 - Canonical rewrite forms

When the line is ready, it should be possible to rewrite it into one of these minimal forms.

Shared-space form

SourceSetFamily      = ...
SourceSetRef?       = ...
SearchSpaceRef         = DeclaredCharacteristicSpace@...
OutcomeSpaceRef        = DeclaredCharacteristicSpace@...
SpaceRefRelationKind   = sameDeclaredSpaceAs
SourceToOutcomeRelation= <direction, mode, carrier>
DistortionPosture      = <posture token; optional note>

Cross-space form

SourceSetFamily      = ...
SourceSetRef?       = ...
SearchSpaceRef         = SearchCharacteristicSpace@...
OutcomeSpaceRef        = OutcomeCharacteristicSpace@...
SpaceRefRelationKind   = distinctDeclaredSpaceFrom
SourceToOutcomeRelation= <direction, mode, carrier>
DistortionPosture      = <posture token; optional note>

If neither rewrite form can be completed honestly, the line is not yet publishable as substrate-bearing text.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.7 - Conditional fields stay conditional

Use SourceSetComposition only when the line genuinely consumes several declared source sets.

When composition is active:

• SourceSetFamily still names the primary family the line is anchored on;
• SourceSetComposition names the additional declared source-set families or the explicit composed-source posture that widens that primary family;
• the composition field does not replace the primary family, and it does not silently retitle the whole line as one different source kind.

Use DerivedViewKind only when one derived view is materially active and the reader must be able to recover that derivation.

Use BasePaletteRef only when a derived tradition or palette view would otherwise hide the recoverable base palette.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.8 - Qualifier refs stay substrate-side

OutcomeMapRef, SpaceMetricRef, TransitionRelationRef, and BridgeDistortionNote are admitted as substrate-side qualifier refs.

Use them when:

• one OutcomeMapRef or named declared map ref really disciplines the source-to-outcome relation;
• one metric really disciplines spread, neighborhood, or comparison claims;
• one TransitionRelationRef really disciplines dynamic coupling or transfer;
• or one bridge-loss note is the relevant reason the relation is qualified.

Do not make those interpretive qualifiers the semantic center of the substrate. They help explain the relation; they do not replace the line made explicit by SourceSetFamily, SourceSetRef?, SearchSpaceRef, OutcomeSpaceRef, and the declared relation/posture pair.

Qualifier semantics are first declared on the substrate side. Later interpretive views may reuse those qualifiers, but they do not become the place where the qualifier is first invented or materially changed.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.9 - Descriptor maps and distance definitions dock here, but do not replace the space refs

When a neighboring line already uses DescriptorMapRef or DistanceDefRef, dock it explicitly:

• DescriptorMapRef may realize or qualify the search-side or outcome-side representation requirement, as the current line requires;
• DistanceDefRef may realize or qualify the metric requirement over that representation on either side, as the current line requires;
• but neither one replaces SearchSpaceRef or OutcomeSpaceRef;
• and CharacteristicSpace remains a different kind from DescriptorMap.

Use this docking rule whenever a reader could otherwise mistake one local representation layer for the whole search-side or outcome-side space reference.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.10 - Publication and shipping remain downstream consumers

G.5 and G.10 may carry metadata such as SelectorOutcomeKind, SetResultFamily, SourceSetFamily, SourceSetComposition, DerivedViewKind, and BasePaletteRef when one selected or shipped result is being published.

That does not mean G.5 or G.10 defines the substrate.

Read the boundary this way:

• this pattern defines the substrate that later publication must preserve;
• G.5 publishes selector-facing outcome metadata;
• G.10 ships publication metadata and pins;
• neither one redefines the search-side reference, the outcome-side reference, or the source-to-outcome relation.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.11 - Ordinary and heavier use

For ordinary use, one short declaration block is enough:

• one SourceSetFamily;
• SourceSetRef? when family-level naming alone would be ambiguous;
• one SearchSpaceRef;
• one OutcomeSpaceRef;
• one explicit SpaceRefRelationKind;
• one explicit relation line;
• one explicit posture line.

Use the heavier stack only when one of these is true:

• several declared source sets are genuinely composed;
• one derived view must stay recoverable;
• one interpretive qualifier is materially active;
• one descriptor-map or distance-definition docking clause is needed to prevent collapse;
• or the reader would otherwise mistake publication metadata for substrate semantics.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.12 - Operator kit: choose, declare, self-check, apply governing neighbor

Use this compact kit whenever the task is practical declaration rather than one more explanatory paragraph.

Use this minimal worksheet when drafting or repairing one substrate line:

SourceSetFamily       = ...
SourceSetRef?        = ...
SearchSpaceRef          = ...
OutcomeSpaceRef         = ...
SpaceRefRelationKind    = sameDeclaredSpaceAs | distinctDeclaredSpaceFrom
SourceToOutcomeRelation = <direction, mode, carrier>
DistortionPosture       = <token; optional note>
Optional qualifiers       = <only those actually active>

Run this self-check before you leave the line:

• if the worksheet cannot be filled without one hidden assumption, the declaration is not ready yet;
• if the next needed prose is mainly "how should the reader inspect this substrate?", continue in A.19.DECLARED-SUBSTRATE-INTERPRETIVE-VIEW;
• if the next needed prose is "what gets published, shipped, retained, or enacted?", apply [G.5](/generated/patterns/G.5), [G.10](/generated/patterns/G.10), [C.19](/generated/patterns/C.19), or [C.24](/generated/patterns/C.24);
• if the current line changes because one neighbor wants different naming, glossing, or repair vocabulary, keep the substrate declaration here and let [F.18](/generated/patterns/F.18), [A.0](/generated/patterns/A.0), or [A.6.P](/generated/patterns/A.6.P) handle that neighboring requirement explicitly.

#A.19.SOURCE-SET-SPACE-SUBSTRATE:4.13 - Using the substrate with neighboring patterns

Once one substrate line is declared, use neighboring patterns in this order:

• Use A.19.DECLARED-SUBSTRATE-INTERPRETIVE-VIEW when the next requirement is interpretive help over the same substrate. The interpretive view may foreground the line, but it does not become the ontology.
• Use G.2 when that interpretation becomes palette-first, tradition-facing atlas work. Keep the base palette and the cited substrate recoverable while doing it.
• Use A.6.P when one passage collapses source set, space ref, interpretive view, atlas view, or map/ref wording into one umbrella word. Repair the wording back to the substrate declaration before adding more theory.
• Use F.18 when the problem is label choice or naming-side comparison around this stack. Naming notes may explain why one head is better named; they do not settle the substrate relation.
• Use A.0 when the task is cold-reader glossing of these tokens. Glosses help recognition; they do not replace the declaration block.

If a neighboring passage would change the source-to-outcome relation or the distortion posture, reopen this pattern first. Neighboring text may reuse the substrate, but it may not silently rewrite it.

Last Updated: 2026-06-17 — upstream FPF commit 646b0b9b (github.com/ailev/FPF)