Status: IN
Patterns systematically migrate across the GoF's Creational-Structural-Behavioral classification: Composite extends from structural substrate to behavioral domain (MacroCommand with order-dependent undo semantics), while Singleton provides sharing infrastructure across all three categories (State subclasses behaviorally, Facade access structurally, factory registries creationally) — demonstrating that the GoF classification is pedagogically useful but architecturally permeable, with patterns serving roles well beyond their classified category.
Composite's cross-domain universality and Singleton's cross-category infrastructure independently validate classification permeability
Depends on (SL): composite-universality-validated-across-structural-and-behavioral-domains, singleton-as-cross-category-enabling-infrastructure