{"id":"changemanager-validates-singleton-as-composition-mediating-infrastructure","text":"ChangeManager's multi-pattern composition (Mediator centralizing Observer's distributed notifications, implemented as Singleton) demonstrates Singleton operating not as mere instance control but as composition-enabling infrastructure: Singleton provides the globally accessible coordination point that makes Observer-Mediator composition operationally viable, validating Singleton's cross-category infrastructure role in a concrete pattern-composition scenario.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["gof-changemanager-mediator-singleton","changemanager-mediator-observer-composition","singleton-as-cross-category-enabling-infrastructure"],"outlist":[],"label":"ChangeManager unifies three cross-category roles (Mediator, Observer, Singleton) validating Singleton's infrastructure function in pattern composition"}],"dependents":[],"metadata":{"source_type":"derived","review_result":"invalid"},"created_at":"2026-06-18T04:21:36+00:00","updated_at":"2026-06-18T06:15:08+00:00","reviewed_at":"2026-06-18T06:15:08+00:00","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"changemanager-validates-singleton-as-composition-mediating-infrastructure","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-changemanager-mediator-singleton","changemanager-mediator-observer-composition","singleton-as-cross-category-enabling-infrastructure"],"label":"ChangeManager unifies three cross-category roles (Mediator, Observer, Singleton) validating Singleton's infrastructure function in pattern composition"},{"node":"gof-changemanager-mediator-singleton","truth_value":"IN","reason":"premise"},{"node":"changemanager-mediator-observer-composition","truth_value":"IN","reason":"SL justification valid","antecedents":["gof-changemanager-mediator-singleton","observer-mediator-distribution-centralization-tradeoff"],"label":"ChangeManager is a concrete case where the abstract Observer-Mediator tradeoff is resolved by composition rather than selection — depth-2 from base + depth-1"},{"node":"observer-mediator-distribution-centralization-tradeoff","truth_value":"IN","reason":"SL justification valid","antecedents":["mediator-centralizes-observer-distributes","observers-more-reusable-than-mediators","gof-observer-unexpected-updates-liability","gof-mediator-centralizes-control-tradeoff"],"label":"Two base beliefs on the relationship + one liability each combine into a unified architectural tradeoff"},{"node":"mediator-centralizes-observer-distributes","truth_value":"IN","reason":"premise"},{"node":"observers-more-reusable-than-mediators","truth_value":"IN","reason":"premise"},{"node":"gof-observer-unexpected-updates-liability","truth_value":"IN","reason":"premise"},{"node":"gof-mediator-centralizes-control-tradeoff","truth_value":"IN","reason":"premise"},{"node":"singleton-as-cross-category-enabling-infrastructure","truth_value":"IN","reason":"SL justification valid","antecedents":["facade-often-singleton","gof-changemanager-mediator-singleton","gof-state-subclasses-often-singletons"],"label":"Three independent Singleton uses across Structural and Behavioral categories demonstrate Singleton transcends its Creational classification"},{"node":"facade-often-singleton","truth_value":"IN","reason":"premise"},{"node":"gof-state-subclasses-often-singletons","truth_value":"IN","reason":"premise"}]}}