Tuple Relational Calculus A nonprocedural query language,where each query is of the form {t|P(t)} It is the set of all tuples t such that predicate P is true for t ■t is a tuple variable t [A denotes the value of tuple t on attribute A f e r denotes that tuple t is in relation r P is a formula similar to that of the predicate calculus Database System Concepts-7th Edition 27.4 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 27.4 ©Silberschatz, Korth and Sudarshan th Edition Tuple Relational Calculus ▪ A nonprocedural query language, where each query is of the form {t | P (t ) } ▪ It is the set of all tuples t such that predicate P is true for t ▪ t is a tuple variable ▪ t [A ] denotes the value of tuple t on attribute A ▪ t  r denotes that tuple t is in relation r ▪ P is a formula similar to that of the predicate calculus