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+Network Working Group                                           4691
+RFC-5                                                           Jeff Rulifson
+                                                                June 2, l969
+
+
+
+                                DEL
+
+
+
+:DEL, 02/06/69 1010:58   JFR   ;   .DSN=1; .LSP=0; ['=] AND NOT SP ; ['?];
+dual transmission?
+
+ABSTRACT
+
+   The Decode-Encode Language (DEL) is a machine independent language
+   tailored to two specific computer network tasks:
+
+      accepting input codes from interactive consoles, giving immediate
+      feedback, and packing the resulting information into message 
+      packets for network transmissin.
+
+      and accepting message packets from another computer, unpacking
+      them, building trees of display information, and sending other
+      information to the user at his interactive station.
+
+   This is a working document for the evolution of the DEL language.
+   Comments should be made through Jeff Rulifson at SRI.
+
+FORWARD
+
+   The initial ARPA network working group met at SRI on October 25-26,
+   1968.
+
+      It was generally agreed beforehand that the runmning of interactive
+      programs across the network was the first problem that would be
+      faced.
+
+      This group, already in agreement about the underlaying notions of
+      a DEL-like approach, set down some terminology, expectations for
+      DEL programs, and lists of proposed semantic capability.
+
+      At the meeting were Andrews, Baray, Carr, Crocker, Rulifson, and
+      Stoughton.
+
+   A second round of meetings was then held in a piecemeal way.
+
+      Crocker meet with Rulifson at SRI on November 18, 1968.  This
+      resulted in the incorporation of formal co-routines.
+
+      and Stoughton meet with Rulifson at SRI on Decembeer 12, 1968.  It
+      was decided to meet again, as a group, probably at UTAH, in late
+      January 1969.
+
+   The first public release of this paper was at the BBN NET meeting in
+   Cambridge on February 13, 1969.
+
+NET STANDARD TRANSLATORS        
+
+   NST   The NST library is the set of programs necessary to mesh
+   efficiently with the code compiled at the user sites from the DEL
+   programs it receives.  The NST-DEL approach to NET interactive system
+   communication is intended to operate over a broad spectrum.
+
+   The lowest level of NST-DEL usage is direct transmission to the
+   server-host, information in the same format that user programs
+   would receive at the user-host.
+
+      In this mode, the NST defaults to inaction.  The DEL program
+      does not receive universal hardware representation input but 
+      input in the normal fashion for the user-host.
+
+      And the DEL 1 program becomes merely a message builder and
+      sender.
+
+   A more intermediate use of NST-DEL is to have echo tables for a
+   TTY at the user-host.
+
+      In this mode, the DEL program would run a full duplex TTY for
+      the user.
+
+      It would echo characters, translate them to the character set 
+      of the server-host, pack the translated characters in messages,
+      and on appropriate break characters send the messages.
+
+      When messages come from the server-host, the DEL program would
+      translate them to the user-host character set and print them on
+      his TTY.
+
+   A more ambitious task for DEL is the operation of large,
+   display-oriented systems from remote consoles over the NET.
+
+      Large interactive systems usually offer a lot of feedback to
+      the user.  The unusual nature of the feedback make it
+      impossible to model with echo table, and thus a user program
+      must be activated in a TSS each time a button state is changed.
+
+         This puts an unnecessarily large load on a TSS, and if the
+         system is being run through the NET it could easily load two
+         systems.
+
+         To avoid this double overloading of TSS, a DEL program will
+         run on the user-host.  It will handle all the immediate
+         feedback, much like a complicated echo table.  At appropriate
+         button pushes, message will be sent to the server-host and
+         display updates received in return.
+
+      One of the more difficult, and often neglected, problems is the
+      effective simulation of one nonstandard console on another non-
+      standard console.
+
+         We attempt to offer a means of solving this problem through
+         the co-routine structure of DEL programs.  For the
+         complicated interactive systems, part of the DEL programs
+         will be constructed by the server-host programmers.
+         Interfaces between this program and the input stream may
+         easily be inserted by programmers at the user-host site.
+
+
+UNIVERSAL HARDWARE REPRESENTATION
+
+   To minimize the number of translators needed to map any facility's
+   user codes to any other facility, there is a universal hardware
+   representation.
+
+   This is simply a way of talking, in general terms, about all the
+   hardware devices at all the interactive display stations in the initial
+   network.
+
+   For example, a display is thought of as being a square, the
+   mid-point has coordinates (0.0), the range is -1 to 1 on both
+   axes.  A point may now be specified to any accuracy, regardless of
+   the particular number of density of rastor points on a display.
+
+   The representation is discussed in the semantic explanations
+   accompanying the formal description of DEL.
+
+INTRODUCTION TO THE NETWORK STANDARD TRANSLATOR (NST)
+
+   Suppose that a user at a remote site, say Utah, is entered in the
+   AHI system and wants to run NLS.
+
+   The first step is to enter NLS in the normal way.  At that time
+   the Utah system will request a symbolic program from NLS.
+
+      REP   This program is written in DEL.  It is called the NLS
+      Remote Encode Program (REP).
+
+      The program accepts input in the Universal Hardware
+      Representation and translates it to a form usable by NLS.
+
+      It may pack characters in a buffer, also do some local
+      feedback.
+
+   When the program is first received at Utah it is compiled and
+   loaded to be run in conjunction with a standard library.
+
+   All input from the Utah console first goes to the NLS NEP.  It is
+   processed, parsed, blocked, translated, etc.  When NEP receives a
+   character appropriate to its state it may finally initiate
+   transfers to the 940.  The bits transferred are in a form
+   acceptable to the 940, and maybe in a standard form so that the
+   NLSW need not differentiate between Utah and other NET users.
+
+
+ADVANTAGES OF NST
+
+   After each node has implemented the library part of the NST, it
+   need only write one program for each subsystem, namely the
+   symbolic file it sends to each user that maps the NET hardware
+   representation into its own special bit formats.
+
+      This is the minimum programming that can be expected if 
+      console is used to its fullest extent.
+
+      Since the NST which runs the encode translation is coded at the
+      user site, it can take advantage of hardware at its consoles to
+      the fullest extent.  It can also add or remove hardware 
+      features without requiring new or different translation tables
+      from the host.
+
+      Local users are also kept up to date on any changes in the system
+      offered at the host site.  As new features are added,
+      the host programmers change the symbolic encode program.  When
+      this new program is compiled and used at the user site, the new
+      features are automatically included.
+
+   The advantages of having the encode translation programs
+   transferred symbolically should be obvious.
+
+      Each site can translate any way it sees fit.  Thus machine code
+      for each site can be produced to fit that site; faster run
+      times and greater code density will be the result.
+
+      Moreover, extra symbolic programs, coded at the user site, may
+      be easily interfaced between the user's monitor system and the
+      DEL program from the host machine.  This should ease the
+      problem of console extension (e.g. accommodating unusual keys and
+      buttons) without loss of the flexibility needed for man-machine
+      interaction.
+
+
+   It is expected that when there is matching hardware, the symbolic
+   programs will take this into account and avoid any unnecessary
+   computing.  This is immediately possible through the code
+   translation constructs of DEL.  It may someday be possible through
+   program composition (when Crocker tells us how??)
+
+
+AHI NLS - USER CONSOLE COMMUNICATION - AN EXAMPLE
+
+   BLOCK DIAGRAM
+
+      The right side of the picture represents functions done at the
+      user's main computer; the left side represents those done at the
+      host computer.
+
+         Each label in the picture corresponds to a statement with the
+         same name.
+
+         There are four trails associated with this picture.  The first
+         links (in a forward direction) the labels which are concerned
+         only with network information.  The second links the total
+         information flow (again in a forward direction).  The last two
+         are equivalent to the first two but in a backward direction.
+         They may be set with pointers t1 through t4 respectively.
+
+         [">tif:] OR I" >nif"]; ["<tif:] OR ["<nif"];
+
+USER-TO-HOST TRANSMISSION
+
+   Keyboard is the set of input devices at the user's console.
+   Input bits from stations, after drifting through levels of monitor
+   and interrupt handlers, eventually come to the encode translator.
+   [>nif(encode)]
+
+   Encode maps the semi-raw input bits into an input stream in a
+   form suited to the serving-host subsystem which will process the
+   input.  [>nif(hrt)<nif(keyboard)]
+
+      The Encode program was supplied by the server-host subsystem
+      when the subsystem was first requested.  It is sent to the user
+      machine in symbolic form and is compiled at the user machine
+      into code particularly suited to that machine.
+
+      It may pack to break characters, map multiple characters to
+      single characters and vice versa, do character translation, and
+      give immediate feedback to the user.
+
+   1 dm    Immediate feedback from the encode translator first goes to
+   local display management, where it is mapped from the NET standard
+   to the local display hardware.
+
+      A wide range of echo output may come from the encode
+      translator.  Simple character echoes would be a minimum, while
+      command and machine-state feedback will be common.
+
+      It is reasonable to expect control and feedback functions not
+      even done at the server-host user stations to be done in local
+      display control.  For example, people with high-speed displays
+      may want to selectively clear curves on a Culler display, a
+      function which is impossible on a storage tube.
+
+   Output from the encode translator for the server-host goes to the
+   invisible IMP, is broken into appropriate sizes and labeled by the
+   encode translator, and then goes to the NET-to-host translator.
+
+      Output from the user may be more than on-line input.  It may be
+      larger items such as computer-generated data, or files
+      generated and used exclusively at the server-host site but
+      stored at the user-host site.
+
+      Information of this kind may avoid translation, if it is already in
+      server-host format, or it may undergo yet another kind of translation
+      if it is a block of data.
+
+   hrp  It finally gets to the host, and must then go through the
+   host reception program.  This maps and reorders the standard
+   transmission-style packets of bits sent by the encode programs
+   into messages acceptable to the host.  This program may well be
+   part of the monitor of the host machine. [>tif(net mode)<nif(code)]
+
+
+HOST-TO-USER TRANSMISSION
+
+   decode   Output from the server-host initially goes through decode,
+   a translation map similar to, and perhaps more complicated than,
+   the encode map.  [>nif(urt)>tif(imp ctrl)<tif(net mode)]
+
+      This map at least formats display output into a simplified
+      logical-entity output stream, of which meaningful pieces may be
+      dealt with in various ways at the user site.
+
+         The Decode program was sent to the host machine at the same
+         time that the Encode program was sent to the user machine.
+         The program is initially in symbolic form and is compiled
+         for efficient running at the host machine.
+         
+         Lines of charaters should be logically identified so that
+         different line widths can be handled at the user site.
+
+         Some form of logical line identification must also be made.
+         For example, if a straight line is to be drawn across the
+         display this fact should be transmitted, rather than a
+         series of 500 short vectors.
+
+         As things firm up, more and more complicated structural
+         display information (in the manner of LEAP) should be sent
+         and accommodated at user sites so that the responsibility for
+         real-time display manipulation may shift closer to the user.
+
+      imp ctrl   The server-host may also want to send control
+      information to IMPs.  Formatting of this information is done by
+      the host decoder.  [>tif(urt) <tif(decode)]
+
+      The other control information supplied by the host decoder is
+      message break up and identification so that proper assembly and
+      sorting can be done at the user site.
+
+   From the host decoder, information does to the invisible IMP, and
+   directly to the NET-to-user translator.  The only operation done
+   on the messages is that they may be shuffled.
+
+   urt   The user reception translator accepts messages from the
+   user-site IMP 1 and fixes them up for user-site display.  
+   [>nif(d ctrl)>tif(prgm ctrl)<tif(imp ctrl)<nif(decode)]
+
+      The minimal action is a reordering of the message pieces.
+      
+      dctrl   For display output, however, more needs to be done.  The
+      NET logical display information must be put in the format of
+      the user site.  Display control does this job.  Since it
+      coordinates between (encode) and (decode) it is able to offer
+      features of display management local to the user site.
+      [>nif(display)<nif(urt)]
+
+      prgmctrl   Another action may be the selective translation and
+      routing of information to particular user-site subsystems.
+      [>tif(dctrl)<tif(urt)]
+
+         For example, blocks of floating-point information may be
+         converted to user-style words and sent, in block form, to a
+         subsystem for processing or storage.
+
+         The styles and translation of this information may well be a 
+         compact binary format suitable for quick translation, rather
+         than a print-image-oriented format.
+
+      (display)   is the output to the user.  [<nif(d ctrl)]
+
+   
+   USER-TO-HOST INDIRECT TRANSMISSION
+
+      (net mode)   This is the mode where a remote user can link to a node
+      indirectly through another node.   [<nif(decode)<tif(hrt)]
+
+
+DEL SYNTAX
+
+   NOTES FOR NLS USERS
+  
+      All statements in this branch which are not part of the compiler
+      must end with a period.
+
+      To compile the DEL compiler:
+
+         Set this pattern for the content analyzer ( (symbol for up arrow)P1
+         SE(P1) <-"-;). The pointer "del" is on the first character of pattern.
+
+         Jump to the first statement of the compiler.  The pointer "c"
+         is on this statement.
+
+         And output the compiler to file  ( '/A-DEL' ).  The pointer "f"
+         is on the name of the file for the compiler output -
+
+   PROGRAMS
+
+      SYNTAX
+
+         -meta file (k=100.m=300,n=20,s=900)
+
+         file = mesdecl $declaration $procedure "FINISH";
+
+         procedure =
+
+           procname (
+
+              (
+
+                 type "FUNCTION" /
+
+                 "PROCEDURE" ) .id (type .id / -empty)) /
+
+              "CO-ROUTINE") ' /
+
+           $declaration labeledst $(labeledst ';) "endp.";
+
+         labeledst = ((left arrow symbol).id ': / .empty) statement;
+
+         type = "INTEGER" / "REAL" ;
+
+         procname = .id;
+
+      Functions are differentiated from procedures to aid compilers in
+      better code production and run time checks.
+
+         Functions return values.
+
+         Procedures do not return values.
+
+      Co-routines do not have names or arguments.  Their initial
+      envocation points are given the pipe declaration.
+
+      It is not clear just how global declarations are to be??
+
+DECLARATIONS
+
+   SYNTAX
+
+      declaration = numbertype / structuredtype / label / lcl2uhr /
+      uhr2rmt / pipetype;
+
+      numbertype = : ("REAL" / "INTEGER") ("CONSTANT" conlist /
+      varlist);
+
+      conlist =
+
+         .id '(left arrow symbol)constant
+
+         $('. .id '(left arrow symbol)constant);
+
+      varlist =
+
+         .id ('(left arrow symbol)constant / .empty)
+
+         $('. .id('(left arrow symbol)constant / .empty));
+
+      idlist = .id $('. .id);
+
+      structuredtype = (tree" / "pointer" / "buffer" ) idlist;
+
+      label = "LABEL1" idlist;
+
+      pipetype = PIPE" pairedids $(', pairedids);
+
+      pairedids = .id .id;
+
+      procname = .id;
+
+      integerv = .id;
+
+      pipename = .id;
+
+      labelv = .id;
+
+   Variables which are declared to be constant, may be put in
+   read-only memory at run time.
+
+   The label declaration is to declare cells which may contain the
+   machine addresses of labels in the program as their values.  This 
+   is not the B5500 label declaration.
+
+   In the pipe declaration the first .ID of each pair is the name of
+   the pipe, the second is thke initial starting point for the pipe.
+
+ARITHMETIC
+
+   SYNTAX
+
+      exp = "IF" conjunct "THEN" exp "ELSE" exp;
+
+      sum = term (
+
+         '+ sum /
+
+         '- sum /
+
+         -empty);
+
+      term = factor (
+
+         '* term /
+
+         '/ term /
+
+         '(up arrow symbol) term /
+
+         .empty);
+
+      factor = '- factor / bitop;
+
+      bitop = compliment (
+
+         '/' bitop /
+
+         '/'\ bitop /
+
+         '& bitop / (
+
+         .empty);
+
+      compliment = "--" primary / primary;
+
+   (symbol for up arrow) means mod. and /\ means exclusive or.
+
+   Notice that the uniary minus is allowable, and parsed so you can
+   write x*-y.
+
+   Since there is no standard convention with bitwise operators, they
+   all have the same precedence, and parentheses must be used for
+   grouping.
+
+   Compliment is the l's compliment.
+
+   It is assumed that all arithmetic and bit operations take place in
+   the mode and style of the machine running the code.  Anyone who
+   takes advantage of word lengths, two's compliment arithmetic, etc.
+   will eventually have problems.
+
+PRIMARY
+
+   SYNTAX
+
+      primary =
+
+         constant /
+
+         builtin /
+
+         variable / (
+
+         block /
+
+         '( exp ');
+
+      variable = .id (
+
+         '(symbol for left arrow) exp /
+
+         '( block ') /
+
+         .empty);
+
+      constant =  integer / real / string;
+
+      builtin =
+
+         mesinfo /
+
+         cortnin /
+
+         ("MIN" / "MAX") exp $('. exp) '/ ;
+
+   parenthesized expressions may be a series of expressions.  The
+   value of a series is the value of the last one executed at run time.
+
+   Subroutines may have one call by name argument.
+
+   Expressions may be mixed.  Strings are a big problem?  Rulifson
+   also wants to get rid of real numbers!!
+
+CONJUNCTIVE EXPRESSION
+
+   SYNTAX
+
+      conjunct = disjunct ("AND" conjunct / .empty);
+
+      disjunct = negation ("OR" negation / .empty);
+
+      negation = "NOT" relation / relation;
+
+      relation =
+
+         '( conjunct ') /
+
+         sum (
+
+           "<=" sum /
+
+           ">=" sum /
+
+           '< sum /
+
+           '> sum /
+
+           '= sum /
+
+           '" sum /
+
+           .empty);
+
+   The conjunct construct is rigged in such a way that a conjunct
+   which is not a sum need not have a value, and may be evaluated
+   using jumps in the code.  Reference to the conjunct is made only
+   in places where a logical decision is called for (e.g. if and
+   while statements).
+
+   We hope that most compilers will be smart enough to skip
+   unnecessary evaluations at run time.  I.e a conjunct in which the
+   left part is false or a disjunct with the left part true need not
+   have the corresponding right part evaluated.
+
+ARITHMETIC EXPRESSION
+
+   SYNTAX
+
+      statement = conditional / unconditional;
+
+      unconditional = loopst / cases / cibtrikst / uist / treest /
+      block / null / exp;
+
+      conditional = "IF" conjunct "THEN" unconditional (
+
+         "ELSE" conditional /
+
+         .empty);
+
+      block = "begin" exp $('; exp) "end";
+
+   An expressions may be a statement.  In conditional statements the
+   else part is optional while in expressions it is mandatory.  This
+   is a side effect of the way the left part of the syntax rules are
+   ordered.
+
+SEMI-TREE MANIPULATION AND TESTING
+
+   SYNTAX
+
+      treest = setpntr / insertpntr / deletepntr;
+
+      setpntr = "set" "pointer" pntrname "to" pntrexp;
+
+      pntrexp = direction pntrexp / pntrname;
+
+      insertpntr = "insert" pntrexp "as"
+
+         (("left" / "right") "brother") /
+
+         (("first" / "last: ) "daughter") "of" pntrexp;
+
+      direction =
+
+         "up" /
+
+         "down" /
+
+         "forward" /
+
+         "backward: /
+
+         "head" /
+
+         "tail";
+
+      plantree = "replace" pntrname "with" pntrexp;
+
+      deletepntr = "delete: pntrname;
+
+      tree = '( tree1 ') ;
+
+      tree1 = nodename $nodename ;
+
+      nodename = terminal / '( tree1 ');
+
+      terminal = treename / buffername / point ername;
+
+      treename = id;
+
+      treedecl = "pointer" .id / "tree" .id;
+
+   Extra parentheses in tree building results in linear subcategorization,
+   just as in LISP.
+
+FLOW AND CONTROL
+
+   controlst = gost / subst / loopstr / casest;
+
+   GO TO STATEMENTS
+
+      gost = "GO" "TO" (labelv / .id);
+
+         assignlabel = "ASSIGN" .id "TO" labelv;
+
+   SUBROUTINES
+
+      subst = callst / returnst / cortnout;
+
+         callst = "CALL" procname (exp / .emptyu);
+
+         returnst = "RETURN" (exp / .empty);
+
+         cortnout = "STUFF" exp "IN" pipename;
+
+      cortnin = "FETCH" pipename;
+
+      FETCH is a builtin function whose value is computed by envoking
+      the named co-routine.
+
+   LOOP STATEMENTS
+
+      SYNTAX
+
+         loopst = whilest / untilst / forst;
+
+         whilest = "WHILE" conjunct "DO" statement;
+
+         untilst = "UNTIL" conjunct "DO" statement;
+
+         forst = "FOR" integerv '- exp ("BY" exp / .empty) "TO" exp
+
+         "DO" statements;
+
+      The value of while and until statements is defined to be false
+      and true (or 0 and non-zero) respectively.
+
+      For statements evaluate their initial exp, by part, and to part
+      once, at initialization time.  The running index of for
+      statements is not available for change within the loop, it may
+      only be read.  If, some compilers can take advantage of this
+      (say put it in a register) all the better.  The increment and
+      the to bound will both be rounded to integers during the
+      initialization.
+
+CASE STATEMENTS
+
+   SYNTAX
+
+      casest = ithcasest / condcasest;
+
+      ithcasest = "ITHCASE" exp "OF" "BEGIN" statement $(';
+      statement) "END";
+
+      condcasest = "CASE" exp "OF" "BEGIN" condcs $('; condcs)
+      "OTHERWISE" statement "END";
+
+
+      condcs = conjunct ': statement;
+
+   The value of a case statement is the value of the last case executed.
+
+EXTRA STATEMENTS
+
+   null = "NULL";
+
+I/O STATEMENTS
+
+   iost = messagest / dspyst ;
+
+   MESSAGES
+
+      SYNTAX
+
+         messagest = buildmes / demand;
+
+            buildmest = startmes / appendmes / sendmes;
+
+              startmes = "start" "message";
+
+              appendmes = "append" "message" "byute" exp;
+
+              sendmes = "send" "message";
+
+              
+           demandmes = "demand" "Message";
+
+      mesinfo =
+
+         "get" "message" "byte"
+
+         "message1" "length" /
+
+         "message" empty: '?;
+
+      mesdecl = "message" "bytes" "are" ,byn "bits" long" '..
+
+DISPLAY BUFFERS
+
+   SYNTAX
+
+      dspyst = startbuffer / bufappend / estab;
+
+      startbuffer - "start" "buffer";
+
+      bufappend = "append" bufstuff $('& bufstuff);
+
+      bufstuff = :
+
+         "parameters" dspyparm $('. dspyparm) /
+
+         "character" exp /
+
+         "string"1 strilng /
+
+         "vector" ("from" exp ':exp / .empty) "to" exp '. exp /
+
+         "position" (onoff / .empty) "beam" "to" exp '= exp/
+
+         curve" ;
+
+      dspyparm F :
+
+         "intensity" "to" exp /
+
+         "character" "width" "to" exp /
+
+         "blink" onoff /
+
+        "italics" onff;
+
+      onoff = "on" / "off";
+
+      estab = "establish" buffername;
+
+   LOGICAL SCREEN
+
+      The screen is taken to be a square.  The coordinates are
+      normalized from -1 to +1 on both axes.
+
+      Associated with the screen is a position register, called
+      PREG.  The register is a triple <x.y.r> where x and y 
+      specify a point on the screen and r is a rotation in
+      radians, counter clockwise, from the x-axis.
+
+      The intensity, called INTENSITY, is a real number in the
+      range from 0 to 1.  0 is black, 1 is as light as your
+      display can go, and numbers in between specify the relative
+      log of the intensity difference.
+
+      Character frame size.
+
+      Blink bit.
+
+   BUFFER BUILDING
+
+      The terminal nodes of semi-trees are either semi-tree names
+      or display buffers.  A display buffer is a series of logical
+      entities, called bufstuff.
+
+      When the buffer is initilized, it is empty.  If no
+      parameters are initially appended, those in effect at the
+      end of the display of the last node in the semi-tree will be in
+      effect for the display of this node.
+
+      As the buffer is built, the logical entities are added to it.
+      When it is established as a buffername, the buffer is
+      closed, and further appends are prohibited.  It is only a
+      buffername has been established that it may be used in a tree
+      building statement.
+
+   LOGICAL INPUT DEVICES
+
+      Wand
+
+      Joy Stick
+
+      Keyboard
+
+      Buttons
+
+      Light Pens
+
+      Mice
+
+   AUDIO OUTPUT DEVICES
+
+   .end
+
+
+SAMPLE PROGRAMS
+
+   Program to run display and keyboard as tty.
+
+   to run NLS
+
+      input part
+
+      display part
+
+         DEMAND MESSAGE;
+
+         While LENGTH " O DO
+
+            ITHCASE GETBYTE OF Begin
+
+            ITHCASE GETBYTE OF %file area uipdate% BEGIN
+
+               %literal area%
+
+               %message area%
+
+               %name area%
+
+               %bug%
+
+               %sequence specs%
+
+               %filter specs%
+
+               %format specs%
+
+               %command feedback line%
+
+               %filer area%
+
+               %date time%
+
+               %echo register%
+
+           BEGIN %DEL control%
+
+DISTRIBUTION LIST
+
+   Steve Carr
+      Department of Computer Science
+      University of Utah
+      Salt Lake City, Utah  84112
+      Phone 801-322-7211 X8224
+
+   Steve Crocker
+
+      Boelter Hall
+      University of California
+      Los Angeles, California
+      Phone 213-825-4864
+
+   Jeff Rulifson
+
+      Stanford Research Institute
+      333 Ravenswood
+      Menlo Park, California  94035
+      Phone 415-326-6200 X4116
+
+   Ron Stoughton
+
+      Computer Research Laboratory
+      University of California
+      Santa Barbara, California  93106
+      Phone 805-961-3221
+
+   Mehmet Baray
+
+      Corey Hall
+      University of California
+      Berkeley, California  94720
+      Phone 415-843-2621
+
+        
+
+