1. Introduction.- 1.1 rexx background.- 1.2 rexx characteristics.- 1.3 rexx applications.- 1.4 REXX's future.- 2. REXX Facilities.- 2.1 Introduction.- 2.2 rexx structure.- 2.3 rexx expressions.- 2.4 Statements.- 2.5 Invocation of a rexx exec.- 2.6 Comparison with CLISTS.- 3. REXX Processing Elements.- 3.1 Introduction.- 3.2 Statements.- 3.3 Routines.- 3.4 Types of instruction.- 3.5 Control processing flow.- 3.6 Assignment.- 3.7 Stack (queue) processing.- 3.8 Parsing.- 3.9 Debugging.- 3.10 Miscellaneous instructions.- 3.11 Commands.- 3.12 Special variables.- 4. REXX Instructions.- 4.1 Introduction.- 4.2 Instruction descriptions.- 4.3 Examples.- 5. Exception Handling.- 5.1 Introduction.- 5.2 Condition traps.- 5.3 Explicit invocation.- 6. String Processing.- 6.1 Introduction.- 6.2 Word parsing.- 6.3 Delimiter parsing.- 6.4 Positional parsing.- 6.5 Dynamic parsing.- 6.6 Argument parsing.- 6.7 Worked examples.- 7. Numbers and Arithmetic.- 7.1 Introduction.- 7.2 Number.- 7.3 Arithmetic operators.- 7.4 Precision and representation.- 7.5 Sequence of operations.- 7.6 Numeric formatting.- 8. Input/Output.- 8.1 Introduction.- 8.2 Data buffering.- 8.3 Opening and closing the data files.- 8.4 Terminal operations.- 8.5 File-mode operations.- 9. Debugging.- 9.1 Introduction.- 9.2 Exception conditions.- 9.3 Tracing options.- 9.4 Trace output.- 9.5 Interactive debug.- 9.6 Parametric debug.- 9.7 Errors with host commands and functions.- 10. REXX Built-in Functions.- 10.1 Introduction.- 10.2 Function definitions.- 10.3 Examples.- 11. Host REXX Commands.- 11.1 Introduction.- 11.2 Host rexx command definitions.- 11.3 Example.- 12. MVS Command Functions.- 12.1 Introduction.- 12.2 mvs command function calls.- 12.3 Invocation of other tso commands.- 12.4 Example.- 13. REXX Invocation.- 13.1Introduction.- 13.2 Invocation from TSO/ISPF.- 13.3 Invocation from batch TSO.- 13.4 Invocation from MVS.- 13.5 Linkage to the host (MVS-TSO) environment.- 13.6 Linkage to programs.- 13.7 Interface with ispexec (ISPF Dialog Manager).- 13.8 Interface with i SRED i T (ISPF/PDF Edit macro).- 13.9 Interface with DB2 (Database2).- 13.10 Interface with qmf (Query Management Facility).- 13.11 Interface from programs with REXX.- 14. System Interfaces.- 14.1 Introduction.- 14.2 General conditions.- 14.3 Invocation of a rexx exec.- 14.4 Interface from programs to rexx processor (IRXEXEC).- 14.5 Program access to rexx variables (IRXEXCOM service).- 14.6 Stack processing (IRXSTK service).- 14.7 Command interface.- 14.8 Function interface.- 14.9 Function package.- 14.10 Load routine - irxload service.- 14.11 Initialisation routine - irxinit service.- 14.12 Get result - irxrlt service.- 14.13 Control blocks.- 14.14 Examples.- 15. Worked Examples.- 15.1 Introduction.- 15.2 Worked example 1.- 15.3 Worked example 2.- 15.4 Worked example 3.- 15.5 Worked example 4.- 15.6 Worked example 5.- Appendix A. Syntax Notation.- Appendix B. Glossary.