Assess students' ability to design and normalize a relational database schema for a small library: identify entities (books, authors, borrowers, loans), define attributes and primary/foreign keys, model relationships including many-to-many (books↔authors) with join tables, specify integrity constraints and indexing considerations, and apply normalization up to 3NF. Include sample scenarios (loaning/returning books, multiple authors per book, borrower loan history) and require an ER diagram, relational table definitions (columns, types, keys), and a brief justification of normalization and constraint choices.