F.6:4.1 - Direct Relation Declaration

performedUnderAssignment : U.Relation
  WorkOccurrenceSlot: U.Work, U.EntityRef
  SystemRoleAssignmentSlot: U.SystemRoleAssignment, U.RelationRef

when performedUnderAssignment(W, RA) obtains:
  attributedPerformerSystem(W, RA) := RA.HolderSystemSlot

WorkOccurrenceSlot names a dated Work already admitted under A.15.1 from independently grounded performance history, A.13-qualified actual performer facts, Method, extent, and containment. The typed slot consumes that completed membership result; F.6 neither helps establish nor reopens W : U.Work. The declaration-local SystemRoleAssignmentSlot names one occurrence of an admitted assignment species declared under U.SystemRoleAssignment. Its U.RelationRef names that occurrence and is limited to U.SystemRoleAssignment. Filling the two slots, matching the holder, or finding temporal overlap does not establish that this Work was performed under this assignment; the case must independently establish that link.

For an obtaining attribution:

S = attributedPerformerSystem(W, RA) = RA.HolderSystemSlot

S is the admitted System already recovered as an actual performer through A.13 and used by A.15.1 to admit W; F.6 does not discover it. RA is the assignment under which that Work is now attributed. The projection exposes the holder already carried by RA only to test equality with S; it creates neither performerhood, Work, attribution, classification, nor a generic assignment occurrence and discards none of RA’s additional participants.

performedBy remains only a deprecated source relation name. Read it through the direct Work-assignment relation only after A.13 and A.15.1 have independently established the actual performer and admitted Work, and after holder equality is checked. New practitioner-facing claims say that the already recovered performer System performed the Work under the assignment, or name performedUnderAssignment when the relation name is needed; they never make the assignment the performer or use F.6 to discover one.

No evidence, log, status, MethodDescription, result, publication, context record, or assignment-state assertion is a generic attribution participant.