Type Theory Skill Overview Expert skill in type theory foundations for implementing type systems including inference, checking, and subtyping. Capabilities - Implement Hindley-Milner type inference with Algorithm W - Implement constraint-based type inference with unification - Design and implement bidirectional type checking - Implement structural and nominal subtyping - Handle variance (covariant, contravariant, invariant) - Implement row polymorphism and record types - Design flow-sensitive type narrowing - Implement type error message generation Target Processes - type-system-implementatio…