MUMPS-11 Language Reference Manual

This document is the official Language Reference Manual for MUMPS-11, an interactive, multi-user, time-sharing system with integrated data management capabilities developed by Digital Equipment Corporation for the PDP-11. It provides detailed information on language elements, expressions, command syntax, and built-in functions. The manual covers the language's character set, programming modes (Direct and Indirect), program structure, data modes (numeric and string), and system variables. It also serves as a detailed reference for various MUMPS commands (e.g., ASSIGN, BREAK, CALL, DO, FOR, GOTO, KILL, LOAD, LOCK, etc.) and provides a summary of system functions (e.g., $ALTERCASE, $CREATE, $EXTRACT, $PIECE, $QUERY, etc.). Appendices include a glossary of terms, the MUMPS character set, and an explanation of error messages.