Adequate pointclass

In the mathematical field of descriptive set theory, a pointclass can be called adequate if it contains all recursive pointsets and is closed under recursive substitution, bounded universal and existential quantification and preimages by recursive functions.^[1][2] This ensures that an adequate pointclass is robust enough to include computable sets and remain stable under fundamental operations, making it a key tool for studying the complexity and definability of sets in effective descriptive set theory.