21.4.1 Accessing Shareable Images in the BASIC
              Environment
  To access a shareable image in the BASIC environment,
  create a shareable image library and place the shareable im-
  age you want to use in that library. See Section 21.4.2 for
  information about creating a shareable image.

  Use the DCL command LIBRARY with the /CREATE and
  /SHARE qualifiers to create a shareable image library. For
  example:
  $ LIBRARY/CREATE/SHARE MYLIB PROG1

  This command creates the shareable image library MYLIB
  and inserts the shareable image PROG1 in that library.

  Once you create a shareable image library, you must define
  the logical name BASIC$LIB n ( n represents a number from
  0 to 9) to point to the library. For example:
  $ DEFINE BASIC$LIB0 DEV$$DISK:[BOB.LIBRARIES]MYLIB

  Once this command executes, a program executing in the
  BASIC environment automatically accesses the library
  MYLIB as a shareable image library to resolve global names.

  Any shareable images referenced by the shareable image li-
  brary must reside in SYS$SHARE, or a logical name for the
  image must specify where the shareable image resides. For
  example:
  $ DEFINE PROG1 DEV$$DISK:[BOB.IMAGES]PROG1.EXE