From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc578.txt | 563 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 563 insertions(+) create mode 100644 doc/rfc/rfc578.txt (limited to 'doc/rfc/rfc578.txt') diff --git a/doc/rfc/rfc578.txt b/doc/rfc/rfc578.txt new file mode 100644 index 0000000..b4e970c --- /dev/null +++ b/doc/rfc/rfc578.txt @@ -0,0 +1,563 @@ + + + + + + +Network Working Group A. Bhushan +Request for Comments: 578 N. Ryan +NIC: 19501 MIT-PTD (DMS) + October 1973 + + + USING MIT-MATHLAB MACSYMA FROM MIT-DMS MUDDLE + An Experiment in Automated Resource Sharing + +I. INTRODUCTION + + This paper describes an experiment in non-trivial automated resource + sharing between dissimilar systems. The goal of the experiment was + to interface the MUDDLE system at MIT-DMS (Host 70.) to the MACSYMA + system at MIT-Mathlab (Host 198.), in such a manner that the MUDDLE- + user at MIT-DMS is not required to know anything about the ARPANET, + Mathlab, or even MACSYMA. In fact, the user need not be aware that + part of the computation is performed by MACSYMA on the Mathlab + computer. + + This experiment differs from the MATHLAB-UCSB/OLS experiment (ref. + NWG/RFC 525, NIC 17161 "MIT-MATHLAB Meets UCSB-OLS" by Parrish and + Pickens) in several important respects. First, the use of the remote + network resource is *completely automated*. The human user does + nothing more than use a function in MUDDLE such as "INTEGRATE" which + requires the remote MACSYMA resource for computation. The program + performs all the required tasks of connecting to Mathlab, log in, and + using MACSYMA. (In the UCSB-OLS experiment, the user had to manually + connect to Mathlab, login, use MACSYMA, type the input in a form + suitable for MACSYMA, save the results in a file at Mathlab, + disconnect from Mathlab, start a retrieval job at UCSB to retrieve + the "saved" results, and finally submit the results to a local + program.) Second, the use of the remote resource is *completely + integrated* into the local MUDDLE system. The user can specify the + computations in a form that MUDDLE understands. The resource-sharing + program (whose existence the user need not be aware of) does the + translation from the MUDDLE "prefix" form to the MACSYMA "infix" form + on input, and vice-versa on output. This ability allows the MACSYMA + resources to be completely integrated into MUDDLE to the extent that + parts of the same computation can be performed by MACSYMA and others + by MUDDLE. + +II. THE MACSYMA AND MUDDLE RESOURCES + + Before proceeding to describe the resource sharing facility a + description of the two resources, MACSYMA and MUDDLE, is in order. + The MACSYMA system at Mathlab is a powerful resource for symbolic + manipulation of algebraic functions. It can, among other things, + + + +Bhushan & Ryan [Page 1] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + perform symbolic integration and differentiation, expand series, + perform Laplace and inverse-Laplace transforms, solve equations and + systems of equations, and simplify rational functions. (A + description of MACSYMA's capabilities is given in "The MACSYMA Users' + Manual" available from the MIT-Mathlab group at Project MAC.) + + The MUDDLE system provides a general-purpose environment suitable for + automatic programming, graphics, data management, "networking", and + mathematical computations. The MUDDLE language represents a powerful + extension of the list processing language LISP in the area of data + types such as strings, vectors, uniform vectors, and user definable + types. (MUDDLE is described in some detail in "The MUDDLE Primer" + (SYS.11.01) by Greg Pfister, available from the Programming + Technology Division at Project MAC.) + + MUDDLE has extensive graphical and numerical computation facilities. + The user can display graphs on ARDS and IMLAC type consoles, and on + the Evans and Sutherland (E&S) display system. The MUDDLE console + graphics provide a facility to view graphical representation of + functions with overlay capability and automatic scaling that can be + controlled by the user. The E&S provides the user with a versatile + tool for studying the dynamic characteristics of graphs, curved + surfaces, and other three-dimensional objects. The combination of + MACSYMA, MUDDLE, and the E&S graphics capabilities represents a very + powerful resource for problem solving that is integrated and made + easily usable by the resource sharing facility. + +III. THE AUTOMATED RESOURCE-SHARING FACILITY + + The resource-sharing facility described herein uses the most easily + accessible communication path to MACSYMA, the TELNET connection to + the logger service on socket 1. No modifications were made to + MACSYMA, nor were any special programs created on the Mathlab + computer. The entire task of resource sharing is performed by + programs in MUDDLE. Let us say on the outset that we are not + advocating this mode of usage for automated resource sharing. A + resource-sharing protocol that allows convenient use of remote + resources via programs is a far more reliable and efficient way, but + that requires work on the part of server sites. The existing + protocols and systems FTP, RJE, RSEXEC, and the Datacomputer cater to + a limited subset of easily managed resources. We register here our + desire for uniformity (which alas is lacking) in the current systems, + and work along the direction of general-purpose resource sharing. In + the absence of a general resource-sharing protocol and a MACSYMA + server to go along with it at Mathlab, the TELNET connection is the + best a user can do. + + + + + +Bhushan & Ryan [Page 2] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + The resource sharing facility comprises of several independent but + integrated parts. These are: + + 1) Connecting to Mathlab, login, and invoking MACSYMA. + 2) Conversion of MUDDLE's prefix to MACSYMA's infix form. + 3) Generation of MACSYMA input. + 4) Interpreting MACSYMA's results including errors and comments. + 5) MACSYMA infix to MUDDLE prefix conversion. + 6) Plotting graphs for the functions. + 7) Allowing human intervention if desired. + 8) Disconnect from MACSYMA. + + The user (assuming that he has loaded the necessary programs in + MUDDLE) to integrate the function "3*X" has only to type: + + >$ + + where '$' represents the ASCII character (or ). + MUDDLE will then return the following result: + + > 2> + + Alternatively, if the user wishes to use the infix form, he can type: + + $ + + and the corresponding answer returned by MUDDLE would be + + "3*X^2/2" + + The following sequence of events takes place when integrate (or any + other function that uses MACSYMA) is used. If the user isn't already + communicating with a MACSYMA (the program keeps track of the + connection), a connection is established to MIT-Mathlab, the user is + logged in (automatically by program, using the user's + identification), and a MACSYMA is initiated. A prefix to infix + conversion is performed and the following input is sent to MACSYMA + (using the above example): + + STRING (INTEGRATE (3*X,X)); + + The program then interprets MACSYMA's output recognizing error + responses and comments and extracts the result if no error is + encountered. The result which is in infix form is then converted to + the prefix form which is returned by the MUDDLE function INTEGRATE. + + + + + + +Bhushan & Ryan [Page 3] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + The INTEGRATE function takes an optional argument, the variable with + respect to which the integration is be performed. The syntax for the + function is: + + + + where EXPR is any expression of the type STRING or QUOTED FORM. The + optional argument (in square brackets) VAR must be of the type STRING + (enclosed by double-quotes). The syntax of other functions is: + + + + + + where TIMES is the number of times the EXPR is to be differentiated + and MAXPOSEX and MAXNEGEX control the maximum positive and negative + integer exponent to be used in expansion. The default value for VAR + is "X", for times is "1", and for MAXPOSEX and MAXNEGEX is "6" each. + + The user can use the result returned by MUDDLE in any of his + computations, including drawing a graph. For example, typing: + + > X -5 5>$ + + to MUDDLE will draw the graph "Y = 3*X^2" on the IMLAC or ARDS screen + with values of X from -5 to +5 (assuming the user has the graphics + package and the right IMLAC program loaded). The same graph would be + drawn if the user typed: + + > X -5 5>$ + + where IPARSE is the MUDDLE function that converts infix to prefix + form. The corresponding function for prefix to infix conversion is + UNIPARSE. + + The details of using the MACSYMA resource sharing facility may be + gathered from the annotated script of the example given in Section V + of this paper. + +IV. CAPABILITIES AND LIMITATIONS + + The program tries to be helpful to the user as much as possible. For + example, if for some reason the MIT-Mathlab computer is not + available, the MACSYMA service at the MIT-AI computer is procured. + + It should be mentioned that though the program is fairly capable in + retrieving results, recognizing error messages, and separating + comments, its recognition is not fool-proof. The program only makes + + + +Bhushan & Ryan [Page 4] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + an educated guess as to where the answer lies: it is not as clever as + a human user sitting at a console, who can filter out such messages + as "System going down" and communication from another user (console- + link) if they were to appear in the middle of the result. This + points to one of the pitfalls of using a facility via a program that + is basically designed for use by human users. + + The program reliability can be marginally improved by asking MACSYMA + to print special characters before and after the results it sends + (but again this is not fool-proof). For example, the following input + to MACSYMA: + + Block ([ans], + print (/(), + ans: diff (X^2,X), + print (string (ans)) + print (/)), + return (ans)); + + will cause MACSYMA to generate the following output: + + ( + 2*X + ) + (D**) 2X + + From the above output, the answer "2*X" can be easily extracted. + + The resource sharing program does however recognize the so-called + "unintegratable" functions such as "EXP (X^2)" -- and gives the + correct error response. Normally, the user is in "TERSE" mode, and + does not see the interaction between MACSYMA and MUDDLE. To see the + interaction the user must enter "VERBOSE" mode by typing: + + $ + + to MUDDLE. To return to "TERSE" mode the user types: + + $ + + The user can also, if he is proficient in use of MACSYMA, communicate + directly with MACSYMA at any point by typing: + + $ + + + + + + + +Bhushan & Ryan [Page 5] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + to MUDDLE. The TELCOM feature may be useful if the user wishes to + see what is going on, or wants to examine the MACSYMA computations by + entering the LISP environment (typing to MACSYMA). To + return to MUDDLE and the automated environment, the user first + escapes to MUDDLE by typing , and then types: + + $ + + to MUDDLE. If the user types "$" after escaping to MUDDLE + from "TELCOM" mode, he will be returned in direct communication with + MACSYMA. If the user discovers that his "MACSYMA" is hopelessly + confused or if he wishes to start a new version of MACSYMA, he must + type: + + $ + + to MUDDLE, which will disconnect him. Typing "$" or using + any of the functions that use MACSYMA will connect him to MACSYMA + again. + + Currently, MUDDLE recognizes and takes action as described above + whenever differentiate, integrate, expand, simplify, and + integrate.simplify (integrate and simplify) functions are + encountered. But it is quite easy to generate programs for other + operations such as Laplace transforms and solving equations. The + prefix-to-infix conversion and vice-versa works for all mathematical + forms we have encountered so far in our short experiment. + + An alternate way to utilize MACSYMA's capabilities would have been to + use it in the LISP environment by constructing a suitable interface + between LISP and MUDDLE. Such an approach would avoid the multiple + conversions from prefix to infix form and vice-versa, but other, + perhaps more difficult, conversions would be required. + +V. EXAMPLE + + The following scenario describes the use of the resource-sharing + facility. The facility is accessible in the MUDDLE system at MIT- + DMS. The interaction between MUDDLE and MACSYMA, normally not + visible to the user, is also shown here (in VERBOSE mode) so that the + reader may gain a better understanding of how the program operates. + It should be noted that the graphs will be plotted only if the user + has loaded the "graphics package" and is on an IMLAC or ARDS console. + We would also like to stress that this scenario is not intended to + demonstrate the full capabilities of MACSYMA, or of MUDDLE, but only + to illustrate the resource sharing facility. + + SCENARIO FOR USING THE MUDDLE-MACSYMA FACILITY + + + +Bhushan & Ryan [Page 6] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + (In the following scenario, user input is underlined and our comments + are preceded with a semicolon. represents a carriage return and + $ represents or alt-mode. The user is assumed to be logged in + at MIT-DMS (Host 70). Note that the input should be typed exactly as + shown, as MUDDLE distinguishes between upper and lower case + characters. Please refer to "THE MUDDLE PRIMER" (SYS.11.01) by Greg + Pfister for a description of the MUDDLE system and to "MUDDLE CONSOLE + GRAPHICS USER GUIDE" (SYS.11.11) by Neal Ryan for a description of + the graphics package. Both documents are available from the + Programming Technology Division at Project MAC.) + +[;]MUDDLE ; Get a MUDDLE, ';' is MONIT prompt. + ---------- +MUDDLE 42 IN OPERATION. +LISTENING-AT-LEVEL 1 PROCESS 1 +$ ; Load the program from MUDDLE +------------------------ ; directory. +/METMUDGIN GOUT +GIN GOUT ; Harmless comments from MUDDLE. +"DONE" +> .X>>$ +------------------------------- +PLEASE BE PATIENT, MACSYMA LOADING MAY TAKE TIME +MACSYMA AT MIT-MATHLAB ; Comments from the program. + ; The result is a MUDDLE form. +>$ +---------------------- +SIN FASL DSK MACSYM BEING LOADED +LOADING DONE ; Comments from MACSYMA. +SCHATC FASL DSK MACSYM BEING LOADED +LOADING DONE +<- <* .X > .X> ; The answer again. +>$; The input is in infix form. +-------------------------------- +"LOG(X^2-X+1)/6+ATAN((2*X-1)/SQRT(3))/SQRT(3)-LOG(X+1)/3" + ; The answer now is in infix form. +>$ +------------------ +"2/(3*((2*X-1)^2/3+1))+(2*X-1)/(6*(X^2-X+1))-1/(3*(X+1))" +$ +-------------- +"X/(X^3+1)" ; We get back the original expression. + 5>>$ +------------------------- +<+ <+ <+ <+ <+ <^ .X 5> <* 10 <^ .X 4>>> <* 40 <^ .X 3>>> +<* 80 <^ .X 2>>> <* 80 .X>> 32> +>>$ +---------------------------- + + + +Bhushan & Ryan [Page 7] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + +RISCH FASL DSK MACSYM BEING LOADED +LOADING DONE +*ERROR* ; Program recognizes that MACSYMA +CANT-INTEGRATE ; couldn't integrate. +LISTENING-AT-LEVEL 2 PROCESS 1 +$ ; To get back to level 1. +-------- +LISTENING-AT-LEVEL 1 PROCESS 1 +$ ; We disconnect here to show the verbose mode, +------ ; the program disconnects automatically on quitting. +"CONNECTIONS CLOSED NOW" +$ +---------- +"YOU WILL BE ABLE TO OBSERVE MUDDLE-MACSYMA INTERACTION NOW" +>$ +----------------- +PLEASE BE PATIENT, MACSYMA LOADING MAY TAKE TIME +MIT MATHLAB PDP-10 STELNT.59 +ML ITS.1. DDT.516. +10. USERS +:LOGIN 70GUEST ; The program uses User's SNAME (GUEST here). +:MACSYMA +THIS IS MACSYMA 226 +SEE UPDATE > MACSYM; FOR CHANGES +FIX 226 DSK MACSYM BEING LOADED +LOADING DONE +(C1) +MACSYMA AT MIT-MATHLAB ; The program announces MACSYMA, + STRING (DIFF ((X^3),X,1)); ; and sends input in infix form. +(D1) 3*X^2 +<* 3 <^ .X 2>> ; The output is in MUDDLE prefix form. +>>$ +----------------------------- +C2) STRING (INTEGRATE ((X/(X+1)),X)); +SIN FASL DSK MACSYM BEING LOADED +LOADING DONE +SCHATC FASL DSK MACSYM BEING LOADED +LOADING DONE +(D2) X-LOG(X+1) +<- .X >> ; The output again. +$ +-------- +"OK" ; Back in TERSE mode now. + +$ ; To load graphics program +---------------------- +IMLAC? (ANSWER Y OR N) Y ; for graphics on an IMLAC. + - + + + +Bhushan & Ryan [Page 8] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + +"DONE" + 2>> X -3 3>$ +--------------------------------------- + ; To graph function sin(X)^2 (graph 1 on Figure 1). +>$ +------------------- + ; To graph diff of sin(X)^2 (see graph 2, Figure 1). +>$ +----------------------- + ; To graph integral of sin(X)^2 (see graph 3, Figure 1). +$ ; To quit from program and MUDDLE. +------- +KILL +[;] ; semicolon prompt from MONIT. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Bhushan & Ryan [Page 9] + +RFC 578 Using MIT-MATHLAB MACSYMA from MIT-DMS MUDDLE October 1973 + + + FIG 1. GRAPH FOR SIN(X)^2, DIFF(SIN(X)^2), AND INTEGRATE(SIN(X)^2) + + + --+--2.0 + | + | + | +++ (3) + | ++++ + | ++ + | + + | ++ + ooo **** --+-- ooo ***+ + o o** ** | o o** + ** + o *o * | o *o + * + o * * | o * + * + o * o * | o * o * + * o * | * + o * + o ** ** |o ** ++ ** +| * | o * | * ++ o | * (1) | +|-------**-------+-----------+++++o+++++-----------+-------**-------| +|-4.0 | o ++ | o | (2) |4.0 + ++ o| o + o + | o + o o | o o + + o | o + + o o | o o + + o o | o o + + ooo --+-- -1.0 ooo + ++ | + + | + ++ | + ++++ | + +++ | + | + | + --+-- -2.0 + + + [ This RFC was put into machine readable form for entry ] + [ into the online RFC archives by Graeme Hewson 3/98 ] + + + + + + + + + + + +Bhushan & Ryan [Page 10] + -- cgit v1.2.3