Status: OUT
Interface inheritance, validated by LSP's behavioral contract framework, is the mechanism that makes abstract coupling and the entire GoF pattern ecosystem sound — without reliable substitutability guaranteed by signature rules, behavioral contracts, and history constraints, patterns based on polymorphic references would silently violate client expectations.
Interface inheritance (depth-1) + LSP as enabler (depth-1) + abstract coupling (depth-1) + LSP completeness (depth-1) unify into the soundness foundation for patterns
Depends on (SL): interface-vs-implementation-inheritance-distinct-roles, lsp-enables-abstraction-dependence, abstract-coupling-enables-pattern-flexibility, lsp-contractual-completeness