A.19.SelectorMechanism:5 - Archetypal Grounding — informative

A.19.SelectorMechanism:5.1 - Tell

When comparisons are partial or set-valued, selection must not pretend there is a single best candidate by default. SelectorMechanism makes selection explicit, policy-bound, and replayable: it returns a set unless criteria explicitly demand otherwise.

A.19.SelectorMechanism:5.2 - Show, U.System example

Scenario. A platform team must pick a set of deployment options for a subsystem under multiple criteria: latency, cost, and regulatory risk. Comparisons are multi-criteria and do not induce a total order.

• CandidateSetSlot = {OptionA, OptionB, OptionC}.

• CriteriaSlot requires Pareto selection over the three unordered pairs {A,B}, {A,C}, and {B,C}, returns all non-dominated admissible candidates, and preserves the full selected set unless an explicit current criterion requires a singleton.

• The finite upstream comparison-application basis covers all three required pairs:

  • exact Compare(OptionA, OptionB, ...) has GuardDecision = pass: OptionB is strictly better than OptionA on latency, while OptionA is strictly better than OptionB on cost under the declared comparator. Its ComparisonResultSlot records those strict opposite wins, so neither dominates the other;
  • exact Compare(OptionA, OptionC, ...) has GuardDecision = degrade because OptionC lacks the required risk attestation, and its output binding contributes no relation token about OptionC; and
  • exact Compare(OptionB, OptionC, ...) has the same explicit degrade basis and likewise contributes no relation token about OptionC.

  The Selector’s ComparisonResultSlot argument is exactly the union of those justified member outputs, so its two tokens both trace to the {A,B} CPM application. No equality, worse-than, or abstain token is fabricated for OptionC.

• MinimalEvidenceSlot? is absent, so evidence is evaluated against CGSpecSlot.MinimalEvidence.

• The actual selection binds the three exact CPM applications and their pair, eligibility, and output bindings; the required-pair coverage and token trace; the deployment-option claim scope and selected regulatory U.ContextSlice members; the same predicate basis or explicit none; the reference plane and evaluation interval; and a degrade policy that permits exclusion of OptionC.

Outcome.

• Under that explicitly bound degrade policy, SelectEligibility returns degrade, excludes OptionC without coercing unknown evidence, and SelectionSlot returns {OptionA, OptionB}.
• If either required comparison involving OptionC instead had GuardDecision = abstain, that basis member would have no output binding, SelectEligibility would return abstain, and no selected-set value would be created. Neither guard value is a member of ComparisonResultSlot or SelectionSlot.
• The dated selection U.Work, actual Select application, finite CPM application basis, evidence-policy and SelectionSlot bindings, and A.10 evidence-provenance path preserve why the reduced-set branch proceeded and why the abstain branch did not.

A.19.SelectorMechanism:5.3 - Show, U.Episteme example

Scenario. A methods group selects a declared set of analysis methods for a task. Candidates are method family refs. The group wants diversity in the selected set, but does not want diversity metrics to silently become dominance criteria.

• CandidateSetSlot = {Family1, Family2, Family3, Family4}

• The selection conditions declare which binary method-family comparisons are required. A finite basis identifies every relied-on CPM application, its exact pair, eligibility value, and own output binding; the Selector’s ComparisonResultSlot argument is their exact justified-token union.

• TaskSignatureSlot is present and is the single policy-default slot or ref:

  • PortfolioMode and dominance regime,
  • budgeting and telemetry hooks (when used).

• CriteriaSlot declares that diversity signals are telemetry unless explicitly promoted by policy.

Outcome.

• SelectionSlot returns a selected set; any archive‑style behavior is a specialization and policy choice, not a hidden kernel default.
• The dated selection U.Work, actual Select application with its TaskSignatureRef.edition and SelectionSlot bindings, and A.10 evidence-provenance path support later explanation without embedding tool tokens into the kernel.