Select Operation Notation:op(r) p is called the selection predicate Defined as: op(=t|t∈rand p(} Where p is a formula in propositional calculus consisting of terms connected by ^(and),v(or),(not) Each term is one of: <attribute> op <attribute>or <constant> where op is one of:=,≠，>，≥.<.≤ Example of selection: o dept_name="Physics"(instructor) Database System Concepts-6th Edition 6.4 @Silberschatz,Korth and SudarshanDatabase System Concepts - 6 6.4 ©Silberschatz, Korth and Sudarshan th Edition Select Operation Notation:  p (r) p is called the selection predicate Defined as: p (r) = {t | t  r and p(t)} Where p is a formula in propositional calculus consisting of terms connected by :  (and),  (or),  (not) Each term is one of: <attribute> op <attribute> or <constant> where op is one of: =, , >, . <.  Example of selection:  dept_name=“Physics”(instructor)