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.