$CASENUM: System Variables$DATE: System Variables$JDATE: System Variables$LENGTH: System Variables$SYSMIS: System Variables$TIME: System Variables$WIDTH: System Variables(: Functions): Functions.: BNF<: Relational Operators<=: Relational Operators<>: Relational Operators>=: Relational OperatorsAND: Logical OperatorsEQ: Relational Operatorsexpression: BNFGE: Relational OperatorsGT: Relational Operatorsinteger: BNFLE: Relational OperatorsLT: Relational OperatorsNE: Relational OperatorsNOT: Logical Operatorsnumber: BNFOR: Logical Operatorsstring: BNFvar-list: BNFvar-name: BNF~=: Relational Operators