/sys$common/syshlp/helplib.hlb PASCAL, Predeclared Routines, Misc, HALT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The HALT procedure  uses  operating  system  resources  to  stop
  execution  of  your  program unless you have written a condition
  handler (using the ESTABLISH procedure) that  enables  continued
  execution.