The previous chapters merely provide an introduction to the Pop-11 language. A more complete definition can be found in the online Poplog REF files.
The rest of this section provides some pointers to further information that might be useful.
Words and identifiers
    words, the dictionary, identifiers, cancel, synonyms,
    valof, idval, identprops, identtype, sections
    (REF * WORDS, REF * IDENT, REF * SECTIONS))
    (HELP * WORDS)
Ascii character codes, special graphic codes in VED
HELP * ASCII, REF * ITEMISE/GraphicsData structures, classes,
    defclass, recordclass, vectorclass keys, conskey, class_print,
    class_apply, etc.
    (REF * DEFSTRUCT, HELP * RECORDCLASS, REF * DATA, REF * KEYS)
Control facilities for use in Pop-11 procedures
    chain, chainto, chainfrom, breakto, breakfrom, catch, jumpout, etc.
     (REF * PROCEDURE, HELP * CONTROL)
Character and item streams
    discin, discout, charin, charout,
    itemiser, incharitem, proglist
    macros, syntax words, and code planting procedures
    (REF * CHARIO,  REF * ITEMISE)
File handling
    syscreate, sysopen, sysread, syswrite, sysdelete, pop_file_versions
    discin, discout, discappend
    (REF * SYSIO)
Pipes and mail boxes
    syspipe, pipein, pipeout
    (REF * SYSIO)
Arrays
    newarray, newanyarray, arrayvector, boundslist
     (REF * ARRAYS)
Interrupt handling
    interrupt, vedinterrupt, popready,
    signal handling (sys_send_signal, sys_signal_handler)
    (See REF * SYSTEM, REF * SIGNALS)
Active variables (with associated procedures that run when the variable
is accessed or updated).
    HELP ACTIVE, HELP DLOCAL, REF IDENT
    REF * active, * nonactive
Dynamic local expressions (expressions whose values are automatically
accessed and saved on procedure entry and restored via updater
procedures on procedure exit):
    HELP DLOCAL
    REF VMCODE has two relevant sections, entitled
        --  Dynamic Local Expressions
        -- More On Dynamic Local Expressions
Processes ("lightweight processes")
    consproc, consprocto, runproc, suspend, resume
    (REF * PROCESS, HELP * PROCESS,
    HELP * ACTOR (may be called NEWACTOR))
Library mechanisms,
    autoloading, search lists, popautolist, popuseslist,
    document browsing facilities, vedgetsysfile
    Different categories of documentation and libraries
    private help (etc) libraries
    (REF * LIBRARY)
`fast_' procedures. Efficiency "tips"
See HELP * EFFICIENCY, REF * FASTPROCSThe garbage collector and memory management procedures.
    sysgarbage, popgcratio, popmemlim, pop_callstack_lim
    (REF *SYSTEM)
Error handling and warnings.
    prmishap, mishap, prwarning, prautoloadwarn, popwarnings
    (REF * MISHAPS)
Timing facilities
    time, profile, timediff, sys_timer,
    (See REF * TIMES)
Debugging, tracing and profiling aids
(REF * TRACE, HELP * DEBUGGER, HELP * PROFILE)Printing
    pr, syspr, sys_syspr, =>, ==>, pop_pr_quotes, pop_pr_radix
    (REF * PRINT)
VED as a general purpose front end
(REF * VEDPROCS, REF * VEDCOMMS, REF * REGEXP from Version 14.5)Calling external procedures
    (HELP * EXTERNAL
    REF * EXTERNAL, REF * EXTERNAL_DATA, REF * DEFSTRUCT)
Saved images
    syssave, sysrestore, sys_lock_system
    (REF * SYSTEM, HELP * MKIMAGE, HELP * SYSSAVE)
Initialisation, and startup files.
    init.p, vedinit.p vedinitfile, vedfiletypes etc.
    (REF * SYSTEM, REF * VEDTERMINALS
    HELP * INITIAL, HELP * TERMINAL, HELP * VEDFILETYPES)
Exiting Poplog
    sysexit and related procedures, popexit, vedpopexit
    ved_xx, ved_qq
    (REF * SYSTEM)
Syntactic sugar available in Pop-11
        switchon
        form
        prefix
Defining new define_forms
HELP * DEFINE_FORMDefining new looping constructs
HELP * FOR_FORMA selection of useful or interesting library packages
    database, add, remove, foreach, forevery,
    sets
    profile
    showtree
    vturtle/turtle
    grammar/tparse/facets
    format
    msblocks
    prefix
Programming style in Pop-11
(TEACH * PROGSTYLE, HELP * EFFICIENCY)The X window facilities in Poplog Pop-11 are very rich and complex. You might start with
    HELP * X
    REF * X
    TEACH * RC_GRAPHIC
    TEACH * PROPSHEET
        (Warning: up to version 14.2 the latter is incomplete!)
For a more complex list of detailed REF files expanding on the
definition of Pop-11 see REF * INDEX
For a list of Pop-11 ref files concerned with the X interface see
REF * XPOPINDEXThe file HELP NEWS always gives information on recent changes to Poplog. It will usually refer you to older versions of the file giving a reverse chronological history of the development of Pop-11 and Poplog. There are other news files for Prolog, Lisp, ML, and X.
The following is an extract from REF * REFFILES
    REF *INDEX
        --- List of REF files
    REF *ARRAYS
        --- Arrays and array procedures (see also HELP *ARRAYS)
    REF¯*ASYNC
        Describes asynchronous traps and signals in Poplog.
    REF *CHARIO
        --- Character stream input and output (See also HELP *IO)
    REF *DATA
        ---  General  data  procedures  and  datatypes  (See  also
        HELP *PROGRAMMING)
    REF *DEFSTRUCT
        --- POP11 syntax for defining and accessing structures
    $usepop/pop/ref/doc_index
        --- This is not a ref file, as explained above.
    REF *DOCUMENTATION
        --- The Poplog online documentation system
    REF *ENVIRONMENT_VARIABLES (Unix only)
        --- Environment variables defined by the Poplog system.
    REF *EXTERNAL
        --- Loading & calling external procedures from Poplog (See  also
        HELP *EXTERNAL, *PROGRAMMING)
    REF *EXTERNAL_DATA
        --- Using external data structures in Poplog
    REF *FASTPROCS
        --- Fast procedures (See also HELP *FASTPROCS, LIB *SLOWPROCS)
    REF *FLAVOURS
        ---  The  flavours  object  oriented  language  (See  also
        HELP *FLAVOURS). Made obsolete by Objectclass.
    REF *IDENT
        --- Identifiers (constants and variables)
    REF *INTVEC
        --- Signed  integer  vectors  (See  also  REF  *DATA,  *VECTORS,
        *STRINGS, HELP *PROGRAMMING)
    REF *ITEMISE
        --- Itemisation and lexical syntax. See also REF *POPCOMPILE
    REF *KEYS
        --- Information on classes and keys (see also HELP *PROGRAMMING,
        *CLASSES, *DATASTRUCTURES)
    REF *LIBRARY
        --- Poplog library mechanisms, including autoloading
    REF *LISTS
        --- Lists and pairs (see also HELP *LISTS)
    REF *LOGICAL_NAMES (VMS only)
        --- Logical names defined by the Poplog system.
    REF *MISHAP_CODES
        --- Some  error  messages  include  a  "code"  abbreviating  the
        message.  This  file  includes  full  explanations  and   cross-
        references to relevant  information about the  error. (See  also
        HELP *MISHAP)
    REF *MISHAPS
        --- Poplog  mishap  (error)  handling (See  also  HELP  *MISHAP,
        *PROGRAMMING)
    REF *NEWC_DEC
        --- Procedures concerned with the "new" interface  to externally
            loaded C programs. See HELP * NEWC_DEC for more details.
    REF *NUMBERS
        --- Number data  types and numerical  procedures (See also  HELP
        *NUMBERS)
    REF *OBSOLETE
        ---   Obsolete   features   still   supported   for    backwards
        compatibility
    REF *POPCOMPILE
        --- POP11 compiler procedures
    $usepop/pop/ref/popindex.*
        --- These files (which  really should be  in another place)  are
        used by the *POPINDEX and *VED_SOURCEFILE mechanisms.
    REF *POPSYNTAX
        --- POP11 syntax in diagram form
    REF *PRINT
        --- Printing procedures, etc (See also HELP *IO, HELP *PRINT)
    REF *PROCEDURE
        --- The nature  of procedures and  closures, list of  predicates
        operating on procedures (See also HELP *PROGRAMMING, *DEFINE)
    REF *PROCESS
        --- The Poplog "process" mechanism. (See also HELP *PROCESS)
    REF *PROGLIST
        --- The  input stream  used in  Poplog by  many system  modules,
        including the  POP11  compiler.  (See  also  REF  *ITEMISE,  REF
        *CHARIO, HELP *PROGRAMMING)
    REF *PROLOG
        --- Procedures that support the Prolog system in Poplog
    REF *PROPS
        --- Properties (association tables) (See also HELP *PROPERTIES)
    REF *PWM
        --- The original Poplog Window Manager (now defunct, as it
        requires Sunview).
    REF *RECORDS
        ---  The  reference  and  boolean  data  types  (See  also
        HELP *RECORDS)
    REF *REFFILES
        --- Overview of REF files, with the information presented here.
    REF *REFFORM
        --- Describes the format of REF files, explains the  conventions
        used  to  indicate  the  types  of  arguments  and  results   of
        procedures, and provides some VED utilities to help creation  of
        REF files in the proper format.
    REF * REGEXP
        --- Describes the Pop-11 regular expression matcher, used in VED
        and other Poplog facilities, for searching in strings.
    REF *SECTIONS
        --- Sections (hierarchies  of permanent  identifiers) (See  also
        HELP *SECTIONS)
    REF *SHADOWCLASS
        --- Mechanisms for bridging the gap between Pop-11 data
        structures and external structures, e.g. for C programs.
    REF *SIGNALS
        ---  Contents now transferred to REF *ASYNC.
    REF *SOCKETS
        --- A set of procedures for creating and operating on Unix
        sockets.
    REF *STACK
        --- The POP11 stack and procedures for operating on it (See also
        HELP *STACK, TEACH *STACK)
    REF *STRINGS
        --- Strings (See also HELP *STRINGS)
    REF *SUBSYSTEM
        --- Describes mechanisms for  handling sub-systems like  Prolog,
        Pop-11, Lisp, ML and switching conveniently between them.
    REF *SYNTAX
        --- Information on POP11 syntax words (See also *PROGRAMMING)
    REF *SYSIO
        --- Device  Input  &  Output  procedures,  including  pipes  and
        mailboxes
    REF *SYSTEM
        --- Various Poplog system control procedures, including starting
        up, interrupts, saving and restoring saved images, etc.
    REF *SYSUTIL
        --- Operating System utility procedures
    REF *TIMES
        --- Date and Time and Timer procedures
    REF *TRACE
        --- Information about tracing Pop-11 procedures.
    REF *VECTORS
        --- Standard full vectors (see also HELP *VECTORS)
    REF *VED
        --- Overview of REF files about the Poplog editor, VED
    REF *VEDCOMMS
        --- Summary of VED <ENTER> commands
    REF *VEDPROCS
        --- Summary of VED system procedures
    REF *VEDTERMINALS
        --- Summary of  VED terminal types  and terminal  initialisation
        procedures
    REF *VEDVARS
        --- Summary of VED's global control variables
    REF *VMCODE
        --- The Poplog Virtual Machine (See also TEACH *VM)
    REF *WORDS
        --- Words and the Poplog dictionary mechanism.
    REF¯*¯WVED
        --- Variables and procedures associated with Windowed VED,
        i.e. XVed and PWM.
There are additional REF files to be found in
    $usepop/pop/x/ved/ref
    $usepop/pop/x/pop/ref
and, at least in Poplog versions 14.5 and 15.0
    $usepop/pop/lib/proto/go/ref
        --- Information about the graphical objects system
    $usepop/pop/lib/proto/objectclass/ref
        --- Information about the objectclass system
In later versions of Poplog those two sets of files may be moved
somewhere else.