tr_lisp.asc Page 1 McESE-FranzLISP: McMASTER EXPERT SYSTEM EXTENSION OF FranzLISP F. Franek Technical Report no TR-22/88

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1 r_lisp.asc Page 1 McESE-FranzLISP: McMASTER EXPERT SYSTEM EXTENSION OF FranzLISP F. Franek Technical Repor no TR-22/88 Deparmen of Compuer Science and Sysems McMaser Universiy 1988 McESE-FranzLISP: McMASTER EXPERT SYSTEM EXTENSION OF FranzLISP (1) INTRODUCTION. F. Franek 1) Dep. of Comp. Sci. & Sysems McMaser Universiy Hamilon, Onario L8S 4K1 Canada TABLE OF CONTENTS: (2) HOW TO MAKE McESE SOFTWARE AN INTEGRAL PART OF FranzLISP. (3) HOW TO MAKE McESE COMPILED KNOWLEDGE BASES PART OF FranzLISP. (4) McESE-FranzLISP SYSTEM BEHAVIOUR.

2 r_lisp.asc Page 2 (5) CONCLUSION. APPENDIX: Index of McESE-FranzLISP funcions; Descripion of individual funcions. REFERENCES Acknowledgemen: 1) Research suppored by SERB and NSERC OGP research grans. ABSTRACT McESE - McMaser Exper Sysem Environmen is a sofware ool designed o help creae problem-specific shells wih imprecise and incomplee knowledge, and fas and compac exper sysems applicaions in a paricular programming language. This is achieved by "exending" he programming language wih a se of commands allowing communicaion wih McESE knowledge bases and McESE special sofware (see [FB], or [FB1]). In his paper implemenaional deails of FranzLISP exension (called McESE-FranzLISP) are presened and discussed. (1) INTRODUCTION. As described in [FB] and [FB1], McESE is a programming environmen for building of exper sysems. Is main feaures include he abiliy o specify he way of handling uncerainy for he whole knowledge base, or for each rule separaely, o uilize compiled rule-form knowledge bases for fas inferring, and he abiliy o build he exper sysem in a paricular programming language. The sofware of McESE is wrien in he programming language C for wo reasons; compac code ha leads o fas execuion, and he abiliy o program in C low-level asks efficienly enough. In his paper he exension of FranzLISP is described and discussed. From now on we may use erm lisp insead of FranzLISP for he sake of breviy. The ask of exending FranzLISP o McESE-FranzLISP consised of wo major asks: - o make he sofware of McESE wrien in C an inegral par of he lisp sysem wih sufficien communicaion beween McESE sofware and lisp sysem wihou disurbing he lisp sysem oo much and wihou a need of exensive re-wriing of he exising McESE sofware. I mus be ensured ha any of

3 r_lisp.asc Page 3 he C funcions of McESE required can be invoked from wihin lisp, and conversely, any lisp funcion, be i buil-in or user defined, inerpreed or compiled, can be invoked from wihin he C funcions; - o make he non-lisp daa srucure of compiled knowledge base (we shall call i knowledge ree in accordance wih [FB] and [FB1]) an inegral par of lisp sysem accessible from wihin lisp, bu proeced from lisp's garbage collecor as long as needed. Of course, here were some oher problems o be resolved as well, e.g. how o simplify invocaion of McESE, how o proec he componens of McESE from he user and so on. (2) HOW TO MAKE McESE SOFTWARE AN INTEGRAL PART OF FranzLISP. Since he kernel of FranzLISP in UNIX is wrien in C, he major lisp funcion eval can be direcly invoked from any C program loaded ino he lisp sysem. To speed up he loading of McESE sofware ino he lisp sysem, he whole McESE sysem is firs compiled as a single source file, and hen loaded ino he lisp sysem using lisp buil-in funcion cfasl. cfasl in fac works as a dynamic on-line loader and so only one linking o he lisp sysem is necessary (he required C funcions may be loaded one a a ime, bu hen many linkings are required slowing down he whole procedure). The individual C funcions needed are hen made available o he lisp sysem (in fac made ino lisp objecs) using lisp buil-in funcion geaddress: (cfasl '/u0/rsch/mcese/lisp/mceses.o '_compiler 'f 100 "c-funcion") (geaddress '_gesizekbree 'f 101 "c-funcion") (geaddress '_loadkbree 'f 102 "c-funcion")... (geaddress '_helpcop 'f 118 "c-funcion") Any of he specified C funcion (e.g. compiler, or gesizekbree) are now inegral par of he lisp sysem and can be invoked from wihin any lisp funcion (e.g. compiler is known in he lisp sysem as f 100, while gesizekbree is known as f 101). The values hey reurned are formaed by he lisp sysem ino lisp values. A more complicaed problem was he problem of invocaion of arbirary lisp funcions from wihin C funcions. Firs, here was he need of invocaion of cvpf's (wrien in lisp) from wihin he inference engine (wrien in C). Cvpf's mus have flonum argumens, and mus reurn a flonum (see [FB], [FB1]). A special C funcion invoke1 provides he service. When McESE sysem is loaded ino he lisp sysem, a global symbol f 1 is bound o he lis (eval (fake addr0)) where addr0 is he address of lisp funcion f 12. The C funcion invoke1 is passed f 1 as an argumen, invoke1 evaluaes f 1 using eval, and ha invokes f 12 which creaes and reurns a lis (eval (lis (fake addr1) flonum... flonum)) back o invoke1. invoke1 pops from a special sack address of he desired lips funcion and insers i ino he lis as addr1, hen i pops from he special sack one be one all (flonum, and hence double in C) argumens and insers hem ino he lis insead of flonum's. Finally, invoke1 erminaes he lis where needed. The las sep involves evaluaing he lis using eval, which in fac invokes he

4 r_lisp.asc Page 4 required lisp funcion wih he specified argumens. The resul of he invocaion (again a flonum, and so double in C) is reurned o invoke1. When a lisp funcion is o be invoked from a C funcion, he address of ha funcion and is argumens are pushed on he special sack, and invoke1(f 1) is called, invoke1 in urns invokes he required lisp funcion (as described above) and passes he value reurned by he lisp funcion ino he C funcion. Second, here was he need of invocaion of predicae service procedures (wrien in lisp) from wihin he inference engine (wrien in C). Predicae service procedures may have any argumens, bu mus reurn a flonum (see [FB], [FB1]). A special C funcion invoke3 provides he service. When McESE sysem is loaded ino he lisp sysem, a global symbol f 3 is bound o he lis (eval (fake addr0)) where addr0 is he address of lisp funcion f 32. The C funcion invoke3 is passed f 3 as an argumen, invoke3 evaluaes f 3 using eval, and ha invokes f 32 which creaes and reurns a lis (eval (lis (fake addr1) (fake addr)... (fake addr))) back o invoke3. invoke3 pops from a special sack address of he desired lips funcion and insers i ino he lis as addr1, hen i pops from he special sack one be one addresses of all argumens and insers hem ino he lis insead of addr's. Finally, invoke3 erminaes he lis where needed. The las sep involves evaluaing he lis using eval, which in fac invokes he required lisp funcion wih he specified argumens. The resul of he invocaion (a flonum, and so double in C) is reurned o invoke3. When a lisp funcion is o be invoked from a C funcion, he address of ha funcion and is argumens are pushed on he special sack, and invoke3(f 3) is called, invoke3 in urns invokes he required lisp funcion (as described above) and passes he value reurned by he lisp funcion ino he C funcion. Third, he explanaion componen of McESE inference engine required o obain in he form of a C sring he lisp prin form of objecs used for he paricular inference (see [FB], [FB1]). invoke7 provides he service. When McESE sysem is loaded ino he lisp sysem a global symbol f 7 is bound o he lis (ge_pname (maknam (explode (fake addr)))))), invoke7(f 7) pops he address of he objec from a special sack, hen using eval evaluaes f 7 which reurns he desired sring. Any oher communicaion beween lisp and McESE programs, e.g. as in mcese:open funcion where he lisp code provides o he C code addresses of required cvpf's and predicae service procedures, is faciliae be lis creaed and inerned in he lisp sysem, passed o he C coded, and eiher used or modified by he C code and hen passed back o he lisp sysem. This kind of communicaion allows he full range necessary and does no inrude upon lisp a all. Given he fac ha FranzLISP's kernel is wrien in C, had more echnical and implemenaional deails of FranzLISP been available, we could have modified our C code o exend he original kernel direcly. This approach did no seem appropriae for he acual differen implemenaions on differen machines may differ, and for o much of inrusion o he sysem. The means we oped for insead do slow he execuion a bi (which is no of such a crucial imporance given he slow execuion of lisp in general) bu allow for exension of lisp independen from he implemenaional deails of FranzLISP's kernel. (3) HOW TO MAKE McESE COMPILED KNOWLEDGE BASES PART OF FranzLISP. When McESE compiler parses and compiles a RSET (see [FB], [FB1]), i all akes place wihin a single call of he C funcion

5 r_lisp.asc Page 5 compiler. Thus all space required is "malloced" in he C program and he whole knowledge ree buil here. When finish, compiler records he knowledge ree in a disk file. The space used is "freed" and conrol reurned back o he lisp sysem. This poses no problems as far as memory managemen. A more complicaed siuaion arises when his compiled knowledge ree is o be loaded o main memory from disk. I mus say in he lisp sysem as long as he user desires while some oher C and lisp funcions are execued. Since he garbage collecor of FranzLISP is invoked auomaically when he sysem has no enough memory available, he knowledge ree mus be proeced agains i. I mus also be proeced agains inrusion by any oher funcion of he sysem. On op of i, when he user does no need he knowledge ree any longer, he memory i akes mus be made available o he sysem again. These requiremens were saisfied by "soring" he knowledge ree wihin a lisp daa srucure, so-called immediae vecor. The C code for loader had o be alered slighly and pariioned ino wo separae funcions. The firs one, gesizekbree, reurns o he lisp sysem he size of he knowledge ree o be loaded (his informaion is sored in he disk file conaining he knowledge ree). Then he lisp sysem creaes an immediae vecor of he required size and binds i o rseid (rse id). The address of he immediae vecor is hen passed o he C program which loads he knowledge ree here absoluizing all address links in he ree (see [FB], [FB1]). Since immediae vecors carry binary daa, here is no problem wih he "conens" being he knowledge ree. As long as his immediae vecor is bound o he rseid, he sysems considers i acive and hence i is proeced from he garbage collecor as well as all lisp funcions. Since he rseid symbolic name is of he form f RSETID# (# sands for a number), and symbols beginning wih f are no available o he user, he likelihood of he user inruding upon he knowledge ree is raher slim, as he has no knowledge of he address of he immediae vecor. On he oher hand, when he knowledge ree is unloaded, he rseid is unbound (and removed from oblis), and so he immediae vecor soring he knowledge ree is no considered acive by he sysem and hence i is for grabs by garbage collecor. From he poin of view of he inference engine and oher componens of McESE accessing he knowledge ree, all hey need o know is he beginning of he ree and correc address links wihin he ree. Thus he fac ha he knowledge ree is inside a lisp objec maers no o hem. (4) McESE-FranzLISP SYSTEM BEHAVIOUR. To invoke mcese sysem, firs invoke FranzLISP from UNIX level by yping lisp'. When in he FranzLISP sysem, load in he mcese sysem by yping (load 'mcese). In a few seconds he sysem is loaded and mcese promp mcese>> will occur: maccs 1 > lisp Franz Lisp, Opus > (load 'mcese) [load /usr/lib/lisp/mcese] [load /u0/rsch/mcese/lisp/mcese.l] [fasl /u0/rsch/mcese/lisp/mcese1.o] [fasl /u0/rsch/mcese/lisp/mcese2.o] /usr/lib/lisp/nld -N -x -A /usr/ucb/lisp -T b3a00 /u0/rsch/mcese/ lisp/mceses.o -e _compiler -o /mp/li lc [McESE-FranzLisp version loaded] *** mcese: please, do no use symbols conaining f (such names are reserved for mcese sysem)

6 r_lisp.asc Page 6 *** mcese: please, do no pu files wih names mcese, mcese.l and mcese.o in your direcory (hese are load files for mcese sysem) mcese>> To make he loading of McESE as simple as possible, he defaul direcory /usr/lib/lisp is used: he file mcese consiss of a single load insrucion specifying wha should be loaded and where i is. Thus he file /u0/rsch/mcese/lisp/mcese.l is loaded. I conains definiion of he new op level and so is no compiled (when compiled i caused some erraic roubles). I also conains load insrucions for /u0/rsch/mcese/lisp/mcese1.o file, which is file wih all lisp funcions of he McESE sysem (hey mainly consiss of lisp code surrounding C funcions checking correcness of argumens and inerpreing he resuls). For faser execuion hese are compiled. I is followed by load insrucions for /u0/rsch/mcese/lisp/mcese2.o file, which conains all insrucion for loading McESE C sofware ino he sysem. A his momen boh, FranzLISP and McESE funcions are fully accessible a all levels of he sysem. Thus: mcese>> (plus 2 3) 5 mcese>> Since all daa srucures and funcions of McESE have names saring wih f, symbols (or srings) conaining f are no available o he user: mcese>> f 1 *** mcese error: using forbidden symbol f f 1 mcese>> (prin "abc f wr") *** mcese error: using forbidden symbol f (prin "abcf wr") There are, of course, ways how o fool he sysem and ge an access o f objecs, bu i is hard o do so accidenally. This all is achieved by redefining he op level of he lisp sysem. The new op level includes he checking for f symbols. The sysem reurns auomaically back o his op level even from lower levels when (rese) is used. mcese>> (mcese:comp 'medrse 'medrse.comp) The above funcion mcese:comp successfully compiled ( was reurned) rse called medrse and he compiled knowledge ree was sored in a disk file called medrse.comp. An inpu racing as well as supression of error recovery may be specified. mcese>> (mcese:load 'medrse.comp) f RSETID0 The above funcion mcese:load successfully loaded he knowledge ree from 'medrse.comp file o he lisp sysem. The rse id f RSETID0 was reurned. mcese>> (seq x (mcese:las-load))

7 r_lisp.asc Page 7 f RSETID0 The above funcion mcese:las-load reurns rse id of he rse mos recenly loaded ino he lisp sysem. mcese>> (mcese:rseidp x) The above funcion mcese:rseidp ess if is argumens is a rse id of an acive knowledge ree. The following funcion mcese:discomp discompiles he loaded knowledge ree, displays i on screen, plus some vial saisics abou he knowledge ree: mcese>> (mcese:discomp x) *** discomp: DISCOMPILE of COMPILED RSET rule med1: pain_in_hroa &.9 * hardship_o_swallow &.4 * noisy_and_mouh_breahing &.6 * headache &.3 * fever &.3 * cough ==> sore_hroa rule med2:.8 * fever &.6 * headache & pain_in_hroa &.7 * hardship_o_swallow &.6 * spoed_hroa &.2 * vomiing & rash ==> srep_hroa_wrash rule med3:.8 * fever &.6 * headache & pain_in_hroa &.7 * hardship_o_swallow &.6 * spoed_hroa &.2 * vomiing &.3 * abdominal_pain &.8 * ~rash ==> srep_hroa_worash rule med4: noisy_and_mouh_breahing & pain_in_hroa & fever &.8 * hardship_o_swallow & ~sore_hroa & ~srep_hroa_wrash & ~srep_hroa_worash ==> onsilliis

8 r_lisp.asc Page 8 rule med5: srep_hroa_wrash & srep_hroa_worash == max ==> srep_hroa rule med6: onsilliis & sore_hroa & srep_hroa == max ==> hroa_rouble [>=.6] rule med7: ~hroa_rouble ==> oher_diseases rule med8: vomiing & abdominal_pain & headache == ff1 ==> oher_diseases *** discomp: RSET saisics follows: level 0 chain: nex pred on level 0: pain_in_hroa (address no know ye) nex pred on level 0: hardship_o_swallow (address no know ye) nex pred on level 0: noisy_and_mouh_breahing (address no know ye) nex pred on level 0: headache (address no know ye) nex pred on level 0: fever (address no know ye) nex pred on level 0: cough (address no know ye) nex pred on level 0: spoed_hroa (address no know ye) nex pred on level 0: vomiing (address no know ye) nex pred on level 0: rash (address no know ye) nex pred on level 0: abdominal_pain (address no know ye) level 1 chain: nex pred on level 1: sore_hroa nex pred on level 1: srep_hroa_wrash nex pred on level 1: srep_hroa_worash level 2 chain: nex pred on level 2: onsilliis nex pred on level 2: srep_hroa level 3 chain: nex pred on level 3: hroa_rouble level 4 chain: nex pred on level 4: oher_diseases pred abdominal_pain: occurs in LHS of rule med3 occurs in LHS of rule med8 pred cough: occurs in LHS of rule med1

9 r_lisp.asc Page 9 pred fever: occurs in LHS of rule med1 occurs in LHS of rule med2 occurs in LHS of rule med3 occurs in LHS of rule med4 pred hardship_o_swallow: occurs in LHS of rule med1 occurs in LHS of rule med2 occurs in LHS of rule med3 occurs in LHS of rule med4 pred headache: occurs in LHS of rule med1 occurs in LHS of rule med2 occurs in LHS of rule med3 occurs in LHS of rule med8 pred noisy_and_mouh_breahing: occurs in LHS of rule med1 occurs in LHS of rule med4 pred oher_diseases: occurs in RHS of rule med7 occurs in RHS of rule med8 pred pain_in_hroa: occurs in LHS of rule med1 occurs in LHS of rule med2 occurs in LHS of rule med3 occurs in LHS of rule med4 pred rash: occurs in LHS of rule med2 occurs in LHS of rule med3 pred sore_hroa: occurs in LHS of rule med4 occurs in LHS of rule med6 occurs in RHS of rule med1 pred spoed_hroa: occurs in LHS of rule med2 occurs in LHS of rule med3 pred srep_hroa: occurs in LHS of rule med6 occurs in RHS of rule med5 pred srep_hroa_worash: occurs in LHS of rule med4 occurs in LHS of rule med5 occurs in RHS of rule med3 pred srep_hroa_wrash: occurs in LHS of rule med4 occurs in LHS of rule med5 occurs in RHS of rule med2 pred hroa_rouble:

10 r_lisp.asc Page 10 occurs in LHS of rule med7 occurs in RHS of rule med6 pred onsilliis: occurs in LHS of rule med6 occurs in RHS of rule med4 pred vomiing: occurs in LHS of rule med2 occurs in LHS of rule med3 occurs in LHS of rule med8 rule med1 uses buil-in CVPF weighed cumulaive evidence rule med2 uses buil-in CVPF weighed cumulaive evidence rule med3 uses buil-in CVPF weighed cumulaive evidence rule med4 uses buil-in CVPF weighed cumulaive evidence rule med5 uses buil-in CVPF max rule med6 uses buil-in CVPF max rule med7 uses buil-in CVPF weighed cumulaive evidence rule med8 uses CVPF ff1 funcion ff1 has 3 argumens (address no known ye) Since he above "discompiled" code can be sored in a disk file insead of being displayed on he screen, mcese:discomp provides a convenien means o reconsruc a RSET from he compiled version of i if need be. The following funcion mcese:unload releases he space aken by he compiled RSET, noe ha afer unloading mcese:las-load indicae ha here are no more loaded compiled RSET's in he lisp sysem: mcese>> (mcese:unload x) mcese>> (mcese:las-load) nil The following funcion mcese:open loads a compiled RSET from he specified disk file o he lisp sysem (or if an rseid is used insead i knows no o load i), hen i loads he (user specified) corresponding FSET, and provides all addresses necessary for he complee knowledge ree. If all proceeded correcly, a kbid (knowledge base id) of he form f KBID# is reurned: mcese>> (seq x (mcese:open 'medrse.comp 'medfse)) [load medfse] f KBID0 The following funcion mcese:las-open reurns kbid of he knowledge ree opened mos recenly: mcese>> (mcese:las-open) f KBID0 The following funcion mcese:kbidp checks if is argumen is a kbid of an acive knowledge ree: mcese>> (mcese:kbidp x)

11 r_lisp.asc Page 11 The funcion mcese:display is like mcese:discomp, only i shows he addresses in he vial saisics par: mcese>> (mcese:display x) *** discomp: DISCOMPILE of COMPILED RSET rule med1: pain_in_hroa &... *** discomp: RSET saisics follows: level 0 chain: nex pred on level 0: pain_in_hroa (address: ) nex pred on level 0: hardship_o_swallow (address: )... rule med8 uses CVPF ff1 funcion ff1 has 3 argumens (address: ) The following funcions mcese:show-inc (mcese:se-inc respecively) reurns he inconsisency level olerance (ses he inconsisency level olerance o he given value respecively) of he specified knowledge base: mcese>> (mcese:show-inc x) 1.0 mcese>> (mcese:se-inc x.7) mcese>> (mcese:show-inc x) 0.7 The following funcions mcese:show-alarm (mcese:se-alarm respecively) reurns he symbolic name of he alarm funcion (ses he symbolic name of he alarm funcion o he given name respecively) of he specified knowledge base: mcese>> (mcese:show-alarm x) nil mcese>> (mcese:se-alarm x 'foo) *** mcese:se-alarm: symbol >>foo<< no bound o a funcion nil mcese>> (defun foo ()) foo mcese>> (mcese:se-alarm x 'foo) mcese>> (mcese:show-alarm x) foo mcese>> (mcese:se-alarm x) mcese>> (mcese:show-alarm x) nil The following funcion mcese:maxinfer-race evaluaes in backward chaining mode he predicae oher_diseases. The inference is execued in racing mode and hence displayed on he screen sep

12 r_lisp.asc Page 12 by sep: mcese>> (mcese:maxinfer-race x 'oher_diseases) is he child's breahing noisy, or does he breah hrough mouh?.3 *** infer: level 0 predicae >>noisy_and_mouh_breahing<< evaluaed o.3 does he child have sore hroa? 1 *** infer: level 0 predicae >>pain_in_hroa<< evaluaed o 1 does he child have a fever? 1 *** infer: level 0 predicae >>fever<< evaluaed o 1 does he child has roubles o swallow?.7 *** infer: level 0 predicae >>hardship_o_swallow<< evaluaed o.7 *** infer: value of predicae >>pain_in_hroa<< used as has been *** infer: value of predicae >>hardship_o_swallow<< used as has been *** infer: value of predicae >>noisy_and_mouh_breahing<< used as has been does he child have a headache? 1 *** infer: level 0 predicae >>headache<< evaluaed o 1 *** infer: value of predicae >>fever<< used as has been does he child have a cough?.7 *** infer: level 0 predicae >>cough<< evaluaed o.7 *** infer: predicae >>sore_hroa<< evaluaed via rule >>med1<< o min =.81714, max = *** infer: predicae >>sore_hroa<< evaluaion: min = via rule >>med1<< max = via rule >>med1<< *** infer: value of predicae >>fever<< used as has been *** infer: value of predicae >>headache<< used as has been *** infer: value of predicae >>pain_in_hroa<< used as has been *** infer: value of predicae >>hardship_o_swallow<< used as has been does he child have spos in his hroa?.5 *** infer: level 0 predicae >>spoed_hroa<< evaluaed o.5 has he child vomied? 0 *** infer: level 0 predicae >>vomiing<< evaluaed o 0 does he child have a rash? 0 *** infer: level 0 predicae >>rash<< evaluaed o 0 *** infer: predicae >>srep_hroa_wrash<< evaluaed via rule >>med2<< o min =.65102, max = *** infer: predicae >>srep_hroa_wrash<< evaluaion: min = via rule >>med2<< max = via rule >>med2<< *** infer: value of predicae >>fever<< used as has been *** infer: value of predicae >>headache<< used as has been *** infer: value of predicae >>pain_in_hroa<< used as has been *** infer: value of predicae >>hardship_o_swallow<< used as has been *** infer: value of predicae >>spoed_hroa<< used as has been *** infer: value of predicae >>vomiing<< used as has been does he child have an abdominal pain?.2 *** infer: level 0 predicae >>abdominal_pain<< evaluaed o.2 *** infer: value of predicae >>rash<< used as has been *** infer: predicae >>srep_hroa_worash<< evaluaed via rule >>med3<< o min =.81, max =.81 *** infer: predicae >>srep_hroa_worash<< evaluaion: min =.81 via rule >>med3<< max =.81 via rule >>med3<<

13 r_lisp.asc Page 13 *** infer: predicae >>onsilliis<< evaluaed via rule >>med4<< o min =.52674, max = *** infer: predicae >>onsilliis<< evaluaion: min = via rule >>med4<< max = via rule >>med4<< *** infer: value of predicae >>sore_hroa<< used as has been *** infer: value of predicae >>srep_hroa_wrash<< used as has been *** infer: value of predicae >>srep_hroa_worash<< used as has been *** infer: predicae >>srep_hroa<< evaluaed via rule >>med5<< o min =.81, max =.81 *** infer: predicae >>srep_hroa<< evaluaion: min =.81 via rule >>med5<< max =.81 via rule >>med5<< *** infer: predicae >>hroa_rouble<< evaluaed via rule >>med6<< o min = 1, max = 1 *** infer: predicae >>hroa_rouble<< evaluaion: min = 1 via rule >>med6<< max = 1 via rule >>med6<< *** infer: predicae >>oher_diseases<< evaluaed via rule >>med7<< o min = 0, max = 0 *** infer: value of predicae >>vomiing<< used as has been *** infer: value of predicae >>abdominal_pain<< used as has been *** infer: value of predicae >>headache<< used as has been *** infer: predicae >>oher_diseases<< evaluaed via rule >>med8<< o min =.4, max =.4 *** infer: predicae >>oher_diseases<< evaluaion: min = 0 via rule >>med7<< max =.4 via rule >>med8<< 0.4 The following funcion mcese:explain displays he informaion how he max (or min) evaluaion of he given predicae was obained during he las inference cycle. mcese>> (mcese:explain 'sore_hroa 'max) max value for predicae >>sore_hroa<< was obained via rule >>med1<< rule med1: pain_in_hroa &.9 * hardship_o_swallow &.4 * noisy_and_mouh_breahing &.6 * headache &.3 * fever &.3 * cough ==> sore_hroa max value 1 of LHS predicae >>pain_in_hroa<< used 1 is he value of he corresponding LHS erm max value.7 of LHS predicae >>hardship_o_swallow<< used.63 is he value of he corresponding LHS erm max value.3 of LHS predicae >>noisy_and_mouh_breahing<< used.12 is he value of he corresponding LHS erm max value 1 of LHS predicae >>headache<< used.6 is he value of he corresponding LHS erm max value 1 of LHS predicae >>fever<< used.3 is he value of he corresponding LHS erm max value.7 of LHS predicae >>cough<< used.21 is he value of he corresponding LHS erm cerainy value of LHS

14 r_lisp.asc Page 14 (as he weighed cumulaive evidence of he LHS values) is RHS predicae >>sore_hroa<< was evaluaed o nil The following funcion mcese:eval reurns (sored) lis of cerainy values obained in he las inference cycle for he specified lis of predicaes: mcese>> (mcese:eval '(sore_hroa srep_hroa onsilliis) 'max) ((sore_hroa ) (srep_hroa 0.81) (onsilliis )) The on-line help is faciliaed by he funcion mcese:help, which allows o brows hrough he help file and/or copy he whole help file o he users home direcory: mcese>> (mcese:help) *** mcese:help (1) ener 'v' o view he help file (2) ener 'c' o copy he help file o your direcory (3) ener 'b' o view and copy (4) ener 'q' o qui q The following funcions mcese:close closes he specified knowledge base, unloading is compiled RSET from he lisp sysem. The funcions from FSET remains in he sysem. They could be removed from oblis one by one, bu i is a raher slow process, so we oped for leaving hem here. The fuure use of McESE- FranzLISP will decide wheher we have o add he removal of FSET o he capabiliies of mcese:close: mcese>> (mcese:close x) mcese>> x f KBID0 mcese>> (mcese:kbidp x) nil mcese>> (mcese:las-open) nil To leave he McESE sysem, jus use lisp funcion (exi): mcese>> (exi) maccs 2 > (5) CONCLUSION. The McESE-FranzLISP is he FranzLISP exension by he McESE sysem. I provides almos full range of McESE capabiliies as described in [FB], [FB1] (he forward chaining and he edior for simulaneous ediing of a rule and is cvpf are no implemened ye, bu will be very soon). Moreover, McESE-FranzLISP provides hree buil-in cvpf; he weighed cumulaive evidence (which reurns he sum of all cerainy values of he LHS divided by he sum of all weighs (see [FB], [FB1]), he max (which reurns he maximal of all cerainy values of he LHS erms), and he min (which reurns he minimum of all cerainy values of he LHS erms). The sysem is being currenly used in he fourh year CS course a McMaser Universiy Archiecure of Exper Sysems, and is graduae version. The sysem saisfies is goals well and can

15 r_lisp.asc Page 15 be a valuable addiion o he reperoire of knowledge engineers, mainly for he abiliy o make fas prooypes in McESE-FranzLISP wih a low overhead coss before he exper sysem is buil in a faser and more compac language (as in McESE-C) uilizing he same McESE knowledge bases as he prooype in McESE-FranzLISP. APPENDIX Index of McESE-FanzLISP funcions (mcese:close '_kbid) (mcese:comp '_rse ['_comp] ['_inrace] ['_errorec]) (mcese:discomp '_rse ['_ou]) (mcese:display '_kb ['_ou]) (mcese:eval ['_kbid] '_predlis '_ype) (mcese:explain ['_kbid] '_pred '_ype) (mcese:help) (mcese:kbidp '_kbid) (mcese:las-load) (mcese:las-open) (mcese:load '_rse) (mcese:maxinfer ['_kbid] '_pred '_objec1... '_objecn) (mcese:maxinfer-race ['_kbid] '_pred '_objec1... '_objecn) (mcese:mininfer ['_kbid] '_pred '_objec1... '_objecn) (mcese:mininfer-race ['_kbid] '_pred '_objec1... '_objecn) (mcese:open '_rse ['_fse]) (mcese:rseidp '_rseid) (mcese:show-alarm '_kbid) (mcese:show-inc '_kbid) (mcese:show-inconsisency '_kbid) (mcese:se-alarm '_kbid '_func) (mcese:se-inc'_kbid '_inc) (mcese:se-inconsisency '_kbid '_inc) (mcese:sufmaxinfer ['_kbid] '_cuoff '_pred '_objec1... '_objecn) (mcese:sufmaxinfer-race ['_kbid] '_cuoff '_pred '_objec1... '_objecn) (mcese:sufmininfer ['_kbid] '_cuoff '_pred '_objec1... '_objecn) (mcese:sufmininfer-race ['_kbid] '_cuoff '_pred '_objec1... '_objecn) (readf) (readi) (reads) (mcese:unload '_rseid) Descripion of individual funcions (mcese:close '_kbid) reurns: nil and displays error messages if errors have occurred, oherwise is reurned. acion: he argumen mus evaluae o a valid kbid. The knowledge base _kbid is closed (i.e. _kbid is no a valid kbid any more), is rule se is "unloaded" from memory. The knowledge base canno be used again unless opened anew. (mcese:comp '_rse ['_comp] ['_inrace] ['_errorec]) reurns: nil and displays error messages if errors have occurred. Oherwise is reurned.

16 r_lisp.asc Page 16 acion: he firs argumen (supplied for _rse) mus evaluae o a name. The second argumen mus evaluae o a name (and i is supplied for _comp), or he second argumen mus evaluae o eiher 0 or 1 (and hen i is supplied for _inrace). The hird argumen mus evaluae o eiher 0 or 1; if he second argumen was _comp, he hird argumen is supplied for _inrace; if he second argumen was _inrace, he hird argumen is supplied for _errorec. The fourh argumen mus evaluae o eiher 0 or 1 and is supplied for _errorec. _rse is he name of a source rule se file. If specified, _comp is he name of a file he compiled _rse should be pu in. If specified, _inrace is he inpu race indicaor. If 1, mcese:comp will display he inpu from _rse on he screen as he parsing and compiling of _rse progresses, if 0, he display of he inpu from _rse is suppressed. Defaul value is 0. If specified, _errerec is he error recovery indicaor. If 1, mcese:somp will coninue compiling even afer an error was found, if 0, afer he firs error mcese:comp sops. Defaul value is 1. (mcese:discomp '_rse ['_ou]) reurns: reurns nil and displays error messages if errors have occurred; if successful mcese:discomp reurns. acion: he value of he firs argumen mus be a valid rseid. The value of he second (opional) argumen mus be a name of a file. If only one argumen is specified, mcese:discomp prins on he screen he conens and saisics of _rse. In case he second argumen is specified, he conens and he saisics of _rse is prined ino he oupu file specified by he value of he second argumen. (mcese:display '_kb ['_ou]) reurns: reurns nil and displays error messages if errors have occurred; if successful mcese:display reurns. acion: he value of he firs argumen mus be a valid kbid. The value of he second (opional) argumen mus be a name of a file. If only one argumen is specified, mcese:display prins on he screen he conens and saisics of he knowledge base _kbid. In case he second argumen is specified, he conens and he saisics of he knowledge base _kbid is prined ino he oupu file specified by he value of he second argumen. (mcese:eval ['_kbid] '_predlis '_ype) reurns: nil and displays error messages if errors have occurred. A sored lis of predicaes and heir values if successful. acion: he firs argumen mus evaluae o a valid kbid (and hen i is supplied for _kbid), or o a lis (and hen he las opened knowledge base

17 r_lisp.asc Page 17 is supplied for _kbid and he firs argumen is supplied for _predlis). If he firs argumen was _kbid, he second argumen mus evaluae o a lis and is supplied for _predlis. The las argumen mus evaluae eiher o max or min, and is supplied for _ype. The _predlis mus be a lis of predicae names. The lis of liss (_predicae _value) {where _value is he max (or min respecively) value of _predicae as inferred during he las inference wih he knowledge base _kbid} is hen reurned, sored according he values (in a descending order). (mcese:explain ['_kbid] '_pred '_ype) reurns: nil and displays error messages if errors have occurred, oherwise is reurned. acion: if only wo argumens are specified, i is assumed ha he las opened knowledge base is used (and supplied for _kbid); he firs argumen (supplied for _pred) mus hen evaluae o a name (symbol), he second argumen (supplied for _ype) mus evaluae o max or min. If hree argumens are specified, he firs one (supplied for _kbid) mus evaluae o a valid kbid, he second (supplied for _pred) o a symbol, he hird (supplied for _ype) o max or min. The explanaion how he max (or min respecively) value of he predicae _pred was obained during he las inference wih he knowledge base _kbid is hen displayed on he screen. (mcese:help) reurns: nil and displays error messages if errors have occurred, oherwise is reurned. acion: a menu of opions is displayed, and he help file is eiher viewed, copied, or boh. (mcese:kbidp '_kbid) reurns: if he value of he argumen is a valid kbid, oherwise nil is reurned. acion: none. (mcese:las-load) reurns: rseid of he mos recen rule se loaded, or nil (if none loaded). acion: none. (mcese:las-open)

18 r_lisp.asc Page 18 reurns: kbid of he mos recen knowledge base opened, or nil (if none opened). acion: none. (mcese:load '_rse) reurns: reurns nil and displays error messages if errors have occurred; if successful mcese:load reurns an rseid. acion: mcese:load opens a file whose name is he value of he argumen, i is assumed o conain a compiled mcese rule se (as produced by mcese:comp). This compiled rule se is hen loaded ino memory and a valid rseid idenifying i is reurned. (mcese:maxinfer ['_kbid] '_pred '_objec1... '_objecn) like mcese:maxinfer-race wihou racing. (mcese:maxinfer-race ['_kbid] '_pred '_objec1... '_objecn) reurns: nil and displays error messages if errors have occurred. Oherwise a flonum beween 0 and 1 (inclusive) or -1.0 is reurned. acion: he firs argumen mus evaluae eiher o a valid kbid (and hen i is supplied for _kbid), or o a name (and he i is supplied for _pred). In case he firs argumen is _pred, he las opened knowledge base is supplied for _kbid. Argumens following _pred are assumed o be lisp objecs o be bound o variables of he predicae _pred. Backward chaining evaluaion of he predicae _pred wih given bindings is performed in maximum mode. The inference is raced on he screen. The resul of he inference is reurned. If ALARM is deeced, he corresponding alarm funcion is invoked. If -1.0 is reurned, he predicae _pred could no be evaluaed. (mcese:mininfer ['_kbid] '_pred '_objec1... '_objecn) like mcese:maxinfer bu in minimum mode. (mcese:mininfer-race ['_kbid] '_pred '_objec1... '_objecn) like mcese:maxinfer-race bu in minimum mode. (mcese:open '_rse ['_fse]) reurns: nil and displays error messages if errors have occurred; reurns

19 r_lisp.asc Page 19 a valid rseid and displays error messages if _rse was loaded successfully bu some oher errors occurred; reurns a valid kbid if boh, _rse and _fse were loaded successfully and he knowledge base was open successfully. acion: he value of he firs argumen mus be eiher a valid rseid, or a name of a file conaining a compiled rule se. In he laer case, he compiled rule se is loaded ino memory and a valid rseid is issued for i. If he second argumen is specified, he file _fse is loaded ino memory (i should conain lisp funcions - CVPF's for _rse). To complee open successfully, all addresses of level 0 predicae funcions, and all CVPF's mus be found. If yes, a valid kbid is issued and reurned and he knowledge base is ready for use. If no all level 0 predicae funcions or CVPF's are found, and error message is displayed and only he valid rseid is reurned. (mcese:rseidp '_rseid) reurns: if he value of he argumen is a valid rseid, oherwise i reurns nil. acion: none. (mcese:show-alarm '_kbid) reurns: nil and displays error messages if errors have occurred, oherwise he name of he alarm funcion for _kbid is reurned. acion: he argumen mus evaluae o a valid kbid. (mcese:show-inc '_kbid) (mcese:show-inconsisency '_kbid) reurns: nil and displays error messages if errors have occurred, oherwise he inconsisency level olerance for _kbid is reurned. acion: he argumen mus evaluae o a valid kbid. (mcese:se-alarm '_kbid '_func) reurns: reurns nil and displays error messages if errors have occurred, oherwise is reurned. acion: he argumen mus evaluae o a valid kbid. Name of alarm funcion for he specified knowledge base _kbid is se se o he value of he second argumen (mus evaluae o a name of an exising lisp funcion).

20 r_lisp.asc Page 20 (mcese:se-inc '_kbid '_inc) (mcese:se-inconsisency '_kbid '_inc) reurns: reurns nil and displays error messages if errors have occurred, oherwise is reurned. acion: he argumen mus evaluae o a valid kbid. The inconsisency level olerance for he specified knowledge base _kbid is se o he value of he second argumen (mus evaluae o a number beween 0 and 1 inclusive). (mcese:sufmaxinfer ['_kbid] '_cuoff '_pred '_objec1... '_objecn) like mcese:sufmaxinfer-race bu wihou racing. (mcese:sufmaxinfer-race ['_kbid] '_cuoff '_pred '_objec1... '_objecn) reurns: nil and displays error messages if errors have occurred. Oherwise a flonum beween 0 and 1 (inclusive) or -1.0 is reurned. acion: he firs argumen mus evaluae eiher o a valid kbid (and hen i is supplied for _kbid), or o a number beween 0 and 1 inclusive (and hen i is supplied for _cuoff). In case he firs argumen is _cuoff, he las opened knowledge base is supplied for _kbid. The argumen following _cuoff mus evaluae o a name and is supplied for _pred. Argumens following _pred are assumed o be lisp objecs o be bound o variables of he predicae _pred. Backwa rd chaining evaluaion of he predicae _pred wih given bindings is performed in sufficien maximum mode wih he cuoff value _cuoff. The inference is raced on he screen. The resul of he inference is reurned. If ALARM is deeced, he corresponding alarm funcion is invoked. If -1.0 is reurned, he predicae _pred could no be evaluaed. (mcese:sufmininfer ['_kbid] '_cuoff '_pred '_objec1... '_objecn) like mcese:sufmaxinfer bu in sufficien minimum mode. (mcese:sufmininfer-race ['_kbid] '_cuoff '_pred '_objec1... '_objecn) like mcese:sufmaxinfer-race bu in sufficien minimum mode. (readf) reurns: nil or a flonum. acion: a flonum is read from he keyboard and reurned. If error, nil is reurned. (readi)

21 r_lisp.asc Page 21 reurns: nil or a fixnum. acion: a fixnum is read from he keyboard and reurned. If error, nil is reurned. (reads) reurns: nil or a sring. acion: a sring is read from he keyboard and reurned. If error, nil is reurned. (mcese:unload '_rseid) reurns: nil and displays error messages if errors have occurred, oherwise is reurned. acion: he argumen mus evaluae o a valid rseid. The compiled rule se _rseid is "unloaded" from memory, _rseid is no a valid rseid any more. The opened knowledge base (if any) conaining his rule se is closed. REFERENCES [FB] [FB1] F. Franek, I. Bruha, McESE - NcMaser Exper Sysem Environmen, submied for publicaion. F. Franek, I. Bruha, The McESE projec, Tech. Rep., Dep. of Comp. Sci. & Sysems, McMaser Universiy, Hamilon, On., Canada, 1988.