This document discusses tuple relational calculus (TRC) and domain relational calculus (DRC), which are nonprocedural query languages for relational databases. It provides examples of queries written in TRC and DRC on sample bank data. It also covers the syntax and semantics of predicates in TRC/DRC, including quantifiers, connectives, and safety conditions for queries to return finite result sets. Expressive power and equivalence between the basic relational algebra and the two calculi are also discussed.