{"id":"changemanager-mediator-observer-composition","text":"ChangeManager concretely demonstrates multi-pattern composition across the Observer-Mediator tradeoff: it centralizes Observer's distributed notifications by acting as a Mediator between subjects and observers, resolving the distribution-centralization tradeoff for the specific case of multi-subject dependency tracking — validating that competing communication patterns can be composed rather than merely chosen between.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["gof-changemanager-mediator-singleton","observer-mediator-distribution-centralization-tradeoff"],"outlist":[],"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"}],"dependents":["changemanager-fully-resolves-observer-cascade-liability","changemanager-resolves-observer-liability-via-pattern-composition","changemanager-validates-singleton-as-composition-mediating-infrastructure","observer-composition-reliability-bounded","observer-designed-for-pattern-composition"],"metadata":{"source_type":"derived","review_result":"pass"},"created_at":"2026-06-17T23:07:32+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-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":"gof-changemanager-mediator-singleton","truth_value":"IN","reason":"premise"},{"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"}]}}