STUDIES on ( 'iim wcnic or Ayro'MTXc co!]?uvat5:o:j Incs»«iisnt»l Data Assivailatior. in Man - Ccsputer Syst-sss) by Licnslic A. Lcnbairdi STUDIES OM THE L^GIC OF Ain'OHATIC CC.f?JJTA7iOH (Ir.ci'o:T:£ntai Dsta Af-siailation in Men - Cat-putcr S73te?ns) by Licneilo Ao Lorafaardi Usssschiisatts Instituta of TechnoJ.ogy SUilHARY T1t3 nain pjs-5b.l<*a :.do3y 5?i3ffii fro:i tho of siodsm ccraputaticn thttcry and ncthod- fact thst conventicnai digii-.ai ccupytei'Sj developed foilowins ths ciESsical idaat? of Turisig f.-:;il to r,S3t raeny r-cqaiiGinsnts ea von JJeisaann^ ©r tei-^inaJ^; of ocsipor-erits textures o iT5r.n=corsputir inforinatioii 3y3tcra cc-np.le.'i sr.d 'fheir main litiitatiors in such context is sc^stiKes idaatixisd as thair eKCOtedingiy hi^h nesds rsgai'-ding the spsoificity of both tha algo. that thsy csn accept for i'xtliT-iS i?.3f:33 t'fis^ not sssi/iTsilation Q;-:ae5.stlon,and p>'s.r;:ariiy 3^?it^;^i2 •j:hro»:i5h able aigorithsjso as orpcitis their dsts^ irhich for iiicr-csjental dcta adaptivaly gs-owing and ineraaentally GCKlifi- Accordingly ^ basic r^sear-ch is boing carried ouv en designing n-w fouKdatlons for> the? icgic of a«tc;.iati.c dij;ital cca-vjtationo '"his pspar- corjsists of ths "xnc5r's;a£n1:ai solution to this of two pr-sliaitiary probes into ths idsd dsclarativs^ CGtsput£r'"i:H bciids for a poijsibia probi'Sajo l^ha first pes't is davotod to d^jvcdoping ths synt^^: cf a prcgrsssaing lar.guaga for such ccraputor baaed on 3 rav5.sion of Karl Kongsp's notation* dc-^ci-Jcd tss;? cr.a.. to discss-d this nctatiori snd to t.'hid-s tha hansn ifs llsough it haa rt-plsfie b^-^fin r^c^ntly it by a Giibstsr.ticilly ko^'S irijTjsdist-aiy rsspotisivaj still this f£i^.t pai't uhould ha ccnsidarxid fi5-3t chsptGrcraipi.tc.vj.on par-'w e2 ( philosophy, of this cuthoi" ia writing c e> Tr.s r.-xj ascend or-^aniaation bssad on t:io idaas of Mswclit n:3soi''y and Siasn^ but en.sblo tha ccnputcz" iistn th£;t an car'iy version cf the asj thsi dsvaXop-riSr.t ccs-sraspcidinw to the accorsd cheptss' of th-s book) pracGnts nsw kind of Shcvj cf the bosk davotsd to «.:h&k--9 to acan to left (Io'S^b irl.^ht such idsas ssyirbolic --'^ revised in a way to sr-a eKprassicns isibaddad in t"s cj'tiimdad L>i'-a;3i6'.-7ic2 s-anr^a)^ not ba siuy if tha li-LV, LIS? or FL?L .list-atr-uctui-ad ifhich wcrJ.d I'saory ori^enisaticn «as^a odop-tcdo Tnare sr-s hfer-a no hiuts to the othax' cheptera, clevotsd to th« dsasign of tha control unit of the fitnations of s;^':3i3olic ticn-j ccsnp-ater a-ad racm'aivs sripraasicns^ its inr-jut-oiitput sy:3t€rSj algov-ithna to cs-Ci'dinate tha infcsviation ficy^ randccs scvC-saaiiig end infoi-^iiticn si'atris^'alj, and idaritifictsticn of dcacilba cs-apiit*? syatess qua'iititatirely j, pji?2:i;3-i:ar3 z'-ss^scti^-^aiy., Jar.viSEV 30. iS53 to , Ttils ..r c.^i-^^r.f'-r Cir^,'-.-., ijfioffBbieci : Ih aevcteo. to ivxrcKincing, « prlfsttive alphabet to tacse forffi v;;'.:.Ti;v:cT cv^^ip'^toi fora-sj;, such 3S the •:7.rhT-> «"'r'e sp'-:=~e :-(ra one .1 '7-.-= • jc/; marks can be ' * ^- •"f ^ht'ir cononicsl dsco'ccositioa cf fcras iat-o a the basic opsx'ation of this theory, aefiae--] Ic tenss of reccx'sive detscanjeatSo -!>^ -j< <^o^)i'^-^ v -^ v, sjhicf' ir^ proved generaH a]-i;b^!.\-'- pnesent.ed in thj.s chapter is restric'ced to a •:.-. of > sarl-ce vb-it^i.ls aecess&ry Toi introducing ryl&6 gad eiesjeiitary ev.*2luation ffi-:?tccxi6, be 3Xt«ndsd in order to aliou - -• i'orT;d u'3«ing the detgchaent Ito Diost important prop-iJ-v !.;- vraicfa .forn3 up.y oro.e'ed co-iple iietacliS'Sut is 8?~-'>t. oi studying prciperti.&3 cf «uch :.. aecantict belti^ Mere in tbe s*s<ins IcxLar aggjeg^ces -» the -'U! r.c;!nputt, rv^jsTb-. c xixe r-'^rr !be definition cf the functions that ' 'iti ths rules by '••soiiaiiing : of fuiict-Jons and raore p.re- foriiiis- Lnter on the i'or mcjxe cnrcpact gereral evaiastiori asethods^ 2«Y bs C^tistfiDii; fw c-r .^ finite 3*j.3uence^ of de. fb-ev =-'v ;; •. vhey r^cttsi'^t of Vln3t«? dlglt«j, at Ieai*fc. ^5:« , rntlot.\£.i, (r«pr«S'--;nt.«^.l t&lsien , Alpha -riijastlc. " , a«fi ^"^ air* six ^^perstiv? cod Yj ^Cii lei vv( I^iBtly, ^r* 1 nt r ctji ucc ^ both ccJi'^.^.v r<-pr';!.»^f;"-Trd 'i.u'iC'i '.).'} '5,'. by •« -;• welt sstsbll^tvi': them ?\i.rt.Uf^' !* herx ; letter, ract function ; • a r^sa:- . -her cor!fc:'?.<«nt« arid dftcloisl • T-'i'jh.le iv >' c :yi: Thcra :;« ' .:v'^' 3 i'f >* re- ,-: rated dxirlng computation. . Forms on 1 2 Sf.ci 1 Any oxiSeTed finite ae^ieiiCe of cu.lca Aj^ vxth-suiv occuri"i»nces n;'.3ijt3 of A pni-ticulsr kind of fsggxegates, referred to as ?£!:«£> pi'-y ciore role 'and neea a thoTX-ugij di^fiisslon ij!ip'...>i-t3n1" jnd sirapi De.t1.at n to '", " . . . ._ se covered -_ ., . -. . Ive mi3rko b.y >jrci , f on-D?3 . rhl.s first, ;:^^ An eggregete^ of dsflnitiou definitaouj irfilctJ alone via I 1 cjsri m 2.-5,. be pr&"/ed £ , forms x'or72 be csiJ.ed cooc-' ci'.'^fj.niblon,-? .1 one! - '" - "^"r c-,-i;y !;• " ' on the bas.l3 as 3,0 :': rXy concstenar.ion 2 it can be pro-vsd thst the .' r:-.'ii r sre atogjir: I'oi-e o.r If s ead b era two 'iggjegytes, the aggregate V1.11 fon:--. ^^^^ ^^'J-^ be a t.o refsixad to qb 3 The first cba fOii<?wing; It ohoai-d ts no^ice.d that punctusr 1 on Esrkr, are cot Ac'Ciiing th^j an f^g^n^^a,. csJ.JE-d si^^rKt-i^rto.: vhieh csn be proved to te i and 2 B finite nuEJbf-.r of For ex-affifie., v-3.Al<?aA. 1,2) Lei- vjs to e-3eh forci su xaxegar. cylleii l^vel, ea CC!? assoei!?»;e The l-jvel ci y/, The levei of ? leveis of jx-vei •TJis of {21..} ri atom Is form 3, ot^slned by concats'ist-Jon o_ o., -ibessB -ibe fo^'m . a^, 'iiid form r:f s_, cbt-3lnfcd by of TLf-v>-'J. .i eccicslng is j ^ in. p-f-.reTi' 1 is a forsi of level. 0, (f), ;.". Ci SUIL fora b? level ((1), .i^ SUM, 3au, -2 and 3.1^^ ili^.t 2*TJ) forts i'cll'jvs ft ora a fla.lte n'Knber 2L.j£^^'^il^'\ JiL lt-3 being; Fox- exsapia^ neither •q [2), )x/ noz ff nor O sre foxas, because one - .jjiLy that no finite seiiucncs iirc.'e It-ious 1. there be icirst at. lastencea of eo,- defiDJ'T-i.or.? ot definirioa 1 is alvaya -and e?.c.h con&letlng of a fjcite seouence of ' 3., such "^^qX each .lastance lo a const-ant 2 and 1. spijllrsd each jnslnnce to the con.catenatiCQ aggregate vblcb. is a fonc, oae pioof, that vlXl be called structurBl Ic-sst. of its b2jng tive isark instances of defin- 3 could prove ^hoa to be ferns ?.f Def iniition h seys that, for r;xoof, o.f oi" applied 5 is r (snclosure la perentheses, respectively, of -iggregates vhicb bsvo baen proved to be Instances of defiaitiOM forras sa result of ox 3 piecedung it jn such proof 2. \., We Kholl alvvsyo RoSusk* that the last >:u.tal prc'Of or sn cpsra- defxaitioa 2 aud of an e^oresaicr. s of any strv.c- i;tatQir«nt Si;sites e being fOT?ao -i Consider subseciu&ncga of st^tsnents of s atructural proof of e conalstliis of etetessents each of which, excluding the first, sppllao to at leeist one ag.sregat« which is s-tated by the precsdins statssaent of the subsequiTice st^jteaent is the Isst- c.-r^e of vUvi to th« proof o p.uniber '* forin If q state- is evidently it. Ws shall ^ilvays assusr^ that etr-uctxirsl pxoof?n do not cents iix such irrelevant Btateaeats The be ecd vhose last gtructtirsl proof- seat doss not belong to soy such ^lubBe-.iuenee, Irxelsvt.T-t . t-o of occvi.rrsnces of icar-ks <, in sn sjigregate e is denoted L(e). An aggregste coastetlag of the la^L c occurreaci?3 of inarks of d forw hs-n'og at ie'ast n ocouxxenceg of L'^arks i?- referred to ^j3 part^lal fora. - ^S??iJ:L.-±^l-lii!£li[!^. t^'S:. l:SMk..B!^'. %^rj:penj5ud cloned var't-u^h ^ia-ii T-^oof! !5y cle.fla.5t.ion Or)vi..vui?v provision j-,iy i'or ixitx-c«3uclxig proof of a form is given by intrc-duct^on T'?:qui.res. closed a ad 5 I>^t nt'sv C i'£, ft ) j>areE>t'a«Be3., ?j C (£,e) r«sp'?;ctiveiy^ t.Jie Theor^a 2; If of a.ll, v; s>rt •'/•;. -.;: UJ (l.) the vhich l.-S,. ojs cp^n oae crciirr;^nre of e i^et 0.«a>^-) the left of op^a and a in e d-f for fo tbe i^ll rlgiit- of sscticn 1^2^ vtiere sli be«n proved of -so?/ cj-ea • ^r- • 9^. (1) i& true for a = C^ l^ec6u;3e In coriSidery tirid reapect to the level, n of V- no onciii'rscces cf :.•. .: is 2 fonti, then, Itiductici-i vtt-b the forirat there £ an. occxiX'r?i>C'5s t.-r; rfe^pectivsly, us prove tho folIov-:(..ig by section total number of oceia rerice* of >.vi- >-'trst 3.> parentbt'sls In C: <:].c»ed par«nUbs£!»?:Sj ; tief init-iori per^inth^sea in couplss of an3. Proof ' part-ntnese^ in the six-uct-mai denote the taf-ai number of j3na In fact, aect-i.oa lo2. 's e ce an aggregate^ an^. let s ba different, frcai o/£,e') -,,-;.l ''1.2 :t v":.r.?;. .ii'jrk .•;.lcsHsd f:S Is; fO' p.t:f-^nt?;;-3??.; tibilf «re t^, .Assunje -:uci\ iu a atnictux^l proof of s^ atui-.>, row ^^..^ •b*'t. r,hi? that the first luBtaoce if definltioa 2 or B-fction .3. say e-, cccitaiaiag a 3s a ccn><j?;: ix-l, e."* tor sad oay e,, -•: t:!:»« b'iC.suGe ssj-, i'orsi eacl.osirrf In «?= one of wiilch^ B&y -ncn-taioa a n. The ri cont3lnJx-g s Bi^ vljiie rt-irtfiij of definition vl3e e vould be or a le-"el great he3 the of ievei corjc-j-s^eTiciv:;:; has xc-vel eji,^ In-stCicces ep'plied to of f- leveK end has proof cennot- conrsin of l-svei n psrv::m,.h'r^ tiie re£«ui it* fhci a-uyi-nr- 2, "i nder 3> partj, .-'.ffis .rn; ox" r,?:!-;,"^-, cae sectiori 1,2. beceuse other- Consequently. « - st.ro.cture % % -• -"^ :. .ji hs^pit- The eorvtr-*but; -. iishe:> ?;b ussntiei 'y in ootu - ueciuo 'oilows by subtrecTJ tii3 by ieu-a^ second ease coatrihaze one aaty ia the second case. pp?vicat.lr.n . '•' ' '-^ the }:i ' cft^'fi f'.r<r.l and ths conclueion fo.Liovs Taeo reta Prccf '^h)% AgaJi . rspeax (Bts) 1* %r\ie if the r*?3;5orijns thne. pravord.. ('.- Let us of ihe proof of tJu;,>rt;in ls\-»3. ix) le.tt- n cl' ('?.), a is 2 (3) sna (U). 3bi ; of iiia ) X-f 3i:d of all s, dU.Terent vanishes by learoa »3n i^ whil^, jpen perenthssis Ixraitiaj^ contributes e unit to the left aaaiber of (8a) and ;he ri<nt oce Anaic-gc^asiy Of^e llieyr&ffi s^:uit)erB case, xhss occurx-eoce of s^jcorai to the none r.heorsrn is thsa^ aOX sli q The coutributicn. of e| to both eJi' la the 'i^s-? eased by hypothesis. e.^'' . a fono. t-bs iiyport-eocs a>id -'•--'h frcic irJ s.1aiiilarly the point of oeflfilng the forms viitxi ;^ If e there sre tvo tilation:^ c-jri . Frr:aE t-his poxnt^ the proof folioys like prove e is 9 form, th^n^ for sil s. Lot s snd b be aggre&3te«M. snd let a he another •itn^eQate con- aisTiog :ihea c'f s sequence of coa6ecut.iv>5 occux-Tencea of oiarkb in e the segregate obtained by replacitsg b for a in called j?ubsr it;..^ -> of b f r a in e ^ik2 a_ vili be deDctad Sfb^^e) an isi 2':oTi! Proof- Lsi: e, then S(b, bs c. -j^,£) X£ -fcr-gio a_ occurrrng In a, t.be -'?!.om Consider^ 3truciiu-^l pxr.cf of e, the inatsace of definition 1.2, stating thQt c is 2 fovK, occurrence b for s ii' Then replace gi?3phlcally of the struct'iral proof foLlowia'?; e in all ststec-ents such insertion, acd th^.n reraove the result, there are section and inseiiv risiit af tsr the above proof of bo e.t.ructur'al .1, in <any one iTTeievj^nt ststacsats frosi ai.l sequeric-e of Tua resulting scs-st. state- racnta is o s-fue*ufai proof of S(bjev«) vtvioh is therefore s fOXIE. 'Ti-'e re-'SBcn for keeping tb/i stateffifnt. that, c is a fora instj^ad of 3irup.ly replectng it with a etructural prnof of b 15 that there taight be occxtTi-^nces of c In s other than So for the concflrpf, of level of ^j dependent of rhe proof tbst ona can 3uch.. 'Tals to give gi'ro proof is not necesHarlly taat an aggregate is xsnliiue, ana It l& easy more than one proof in possible. Cense- ex5n4>ls>s wcicre quent'.Ly, Q_^ form has besn envJoaged as the level is aot a priori unique^ but I'C ts uecessaAy of its imxqueaess. for fuxther developasnt to give 3 -prooi Before doing this, hovevar, It handy to introduce concept r ^re yhall c.'^ll 1-3 s view ieft__5egr^ snd £ifM,££H:b.' respectively, of ths occucrence of « tmiK a different frcsn p5renth«8ls la an 1.0- ^.,.^1'£) By IheoretD ^. (£'£.) "-" ^9^) ^^ «£'£) ' r'eixher dept-ia Is ever nfgstlve wbea t is e lofo). 5, Tfaeorga J^^__f'^f f^>'^ ^'^.,„'r^p^:^^?- o^ occurrences cf a toirs In s , ".• _ e the level of e ii, this fnoorea is rh« Tiie vasia con&eqvis-ace of a gu-ar^ntea fact, that cf the liijiqueaess of Iks level of ^ny xt px'OYides i-^-^r Proof: Kotjce firfot that- esch cccurreucs of definltiOii section U. occui-rene depth 0. re fact:, 1,. yliicb tbexefore has no occurreace of definition issxlsurn i-.iie of the oa^s of section 1^2, jSeids 2^ level of occurr-ences of stems is tbs tb-e fonus vblch sre conc-Jte-nated ; in by leQ22« I applied to Bny tvo foi^& e. aod Sp, the coacat- en.^t.^OQ of e^ and e^ a'?es ;'acva'rence ezry 0, cf piirsntheaes sad whose only atom has consequently E;>ch fcrn's -i/iere k;^x:5du'3 yields 6 for^ of level y r.ct, yield any chenge in the of atoms in either e, oi- e^ . de.i.-t.h of Each occuireace of definitiorLH; section 1^2, Increaees by one the depth of all iff :ctiici. thi fiarse occurr.=:,oces cf atoois. Ihen all tiirae definite one ;yieid gcieratloa 01 varisticn hoth of cKxlmum depth end level, Ttis applies In particular to any sequence of occvlxtsqcc-s of (! :f initicue :'.roof of ej 1. ' co:'. "^^ section 1 = cou?Mr.utla^ 2, the theoret:i = i; stnactural -11- Xf a denotes in 'i^Iic av. fiS;;rogatc. reverse oriSer ana let a~" vhaxx-; dcniot.o the inverae agsJ^gatc open pareiit>?,ese3 ere repieced by closed ones in hII of tbaii* ccciirvances, end vies versa » there Prcyo£'- cy s\ibRi3t.'5 the following la fact, n structural procf oiiiipl;;,- Then i invertilag tiis order of all couples of for^s vhich are concotenated by occurrerices of defiuition in the Gtvniotural proof of a. 2_j section 1„2„, ; e be .ei. fora of -a ie'w;i.v n .lad ,l^': uo define th^ ii,^'? C, v r'''<- 7.: '•l e, of coij-raas TttC" <5 pcslti^-e jnt'cgeTj m £.. e_ Is bssed TI t,here sre no such on. srid . . .;-:; ;;-j e,.,- , c are If (here ere e-J such tije •#;.il.e ^har? of g Fxoof lis - £4 ; Let *>:?vi c--53!K'iS. _ ^ id sben M(e) = m, v.rireaces pxec2ding tae first of coapoii.entg oe.ciirr&ucea in'-: aggvcjTat-es ^;nces e,, ';J«-rfao.t.3 occ--. M(e) = i and the eaaonlcal decowposit ion of e Is e, -o be unaecomposable :. eaLled nuxaber of canonical cscoaicsl dvicoajscsitica of of aeptb .' element '^'stioa^ ci»l :.-r.~; ' ' or ioxluving tba (i— 'S^^fir'f*'^ ' .' ' is tbe Is obvious - prove This -fbeoreia for the eanonlcsX eosrporsenb e i ^<="^-- nicturaX pruc-f or e^ c of Soch e, :r. .i ,'roof . c„ Let tb>r: Mi>'5C.r<im. <5ri ijs --a r—- "igh^ of e^ In e, In f'e-ct^ hii'/e deprij let u--3 call it 3^ section in e,-, i-.2. 'JtieT-efors-, In this case t cencot becaii-AJe? t J.s statias- that e* Is s forns beceuse it 2, of deptb rtomi^i «c<5 suppose they vers not: of ^iHfivAtiav: j'n&t-a'.jce &^ contyinias are identicel, vhlch vaalA prove ;r. _ 3bf..''' could CO ioiiger definition -^ggr-egflte be an occurrence of j'o:-.;;;,, oit;b.er to. the; be atatlng that an if it veie- aa occxirr«-nce of -Is t-he concstona" coimB liD-lxmc; such concatenrit.ioa. which aust be in e,, ocbsrwise altber e^ or depth in &>'.. I.st aad coat-'Jln e..> ej? woii/id atetOKant yle-ldiiig a foxTO vij:; S. '.fOu.Vd cental us ng «. shew that c^- not be the firGv. FurtberBOr'j has slso depth c*' KXist have in e. In f3ct.> each ei^staimnt of the sti^ictur'ai proof of erctslng the depth of c* vould also raiee ^se one of £j sad v'as s»ae depca dsptii in e., i:i e.. vtiich Is 0.. c-f-' and. Eort e. g lotist confieiiuently ii^ve e.>5rmot contcln coansae of -?mich ends the proof of the theoieiCc : SeclvvaJ. per? .;> ^sl,..;^: Let us call gBri'^^bXe Ic . . ^ the enclosure xa psjentijefje-s of varisbi? raark x : of Vevel 1 cor-siisting of js t-fae c ones taxation 3ud ^ positive iritf^ger, of -Cie called subscript,^ For ex«cpi.e» the ioxm ' (x,8) (1) cyntux before iatroduciag ar It- .Ujpoo3lW.e 3o .13 ^<>:;::'''or^ ;:-.voc>th acqua:. a.^o-ata.T shcnjild ^-t^ f •>'• fsir Conssoiuently^ eic-s?eat3c r.l •: :;>tiin5 to sny nacatiou,, Uuig^iSge of fche 3bstr9c!^ jji^iCiYed bj* re^diiig '"•he letter vai'icblr? ?ar ex3mpley ;_ nr! Xi4isr-3 ^tsri-sble lettfri- (x,r) t suca thac : --' :. eubscr: ^ •; 3C-quei j1 a : .rs protectica .^geinst . ^ thst the iu:c on trolled 'let v be sjn We have the foiiowing e.. S(b;.v,e) . -as? :y... of ' ccry:^ groifing of the Jshters while cotnputatiCns progicese -roile and verl 2bie lett«r In cleaj; : - ' rher t '^r. th- VJ l--i- ^^'-" U,£, ^ Tb.eore;Ti 1- 0< ever c-ccurs M^Jesii; occurreaca of . ^ Frcr-f- Tn. fact be 1-hjs ca-i pr':r^'od U£.t.d tc px'ove The thai-; 3b, stating be vrfth 3 -nDnicsi form that, a itton 2, enatsd 'ive dejri:.h.- f.1.rftt of definition Nox' can t- b;ii 11. v^ 1, section it could of theorem Tola proof csn an 3 such The If i,?,, r-or. fce c_ jfYous sccrjorj I.,U orje s'' difi'ers iriBtanc* of dsfin- cf the tvo ccacat- or coj^ia of %.v. ni»i.y4- 'iaiae parc-ntnesen sn this pzur/c, tie pj-oof follcws 1.'... be extended to the csee viaere v In contrasts if „'Oulcl ttiil be tree but should, be pi'tivcid in .;5 differ- is a fora, the largest of fill vslusa of the subset ic-t.s of '^''^ ., cannot obviously aad if sii ar.om of any -ondeccrcrjcs able foma.. tiie v-3riable 3ett..?.r^> Lf^t 2. section has several com;poa'*ats< this proof -fould no longer hold» th^yort-ia £;_ Iniffir-dlately c-cci-u-reace TcTTs. form.; K^re it vould sncloec ••-, one fcti^ an Instsince of deflaitton 3y -SS^sgste already coatsining v. on-': to noti-irxei^^vanr. sr^steecent t vcuid have an occurrence an section, becs^oss if J the corjt-!>la (3<rra'T5)oaatij.oa rJtieorc:% BCctJon, because If it vers {sanre fortarii like ihe rjMtzt taE. sLrailtir contsicius v i& a e'^ the forra occurring in frova technique 8t by considering tlw i3i>tsac£- itj gtructursj. pr-xif of e ''he tbat the variable l&'tter occxvrring la v is a form; Etatercf^n*. of s wrll he denoted K(£)> foniiSj and suppose ^V- K(h) j^ ^^^ Suppose favthyr that, b ha& that, '2^ ?i to-^vTl of k, (ic'-i^O), occurrences of righf"- by denot-sng ac Mie variable letter by obteliJied fro-?' o letter (£ji, ^ >i(B,) Theorens i. I?/ .?or e.f.^.sxple. (x.l)* 2. ?*, a c$ ((x, Ari<:'%h;^i- ?,'i i^i 3l::?o Dperty cr ;i are both the x-'ssult d-znare ) couei.der a new foro "- otherviee tbs i,,-^-^ i^*v> form is called partly! ciet\ot:,rd derachraent of t-«o fores 2)., c-;:.>a:^-act f^rfrtiai occurrences of e •,;.3 (x, 1 C:r:^r^k), the nev v^riabl*; h^^^.sJ- of e. This from a snd tiie purtta'i. J.et 1*' I<--: v^, iic, l)'i ; i'cy:;i sii^gl<» and HU) fore, 1^-t b is 1, t.bat dc:tac:a::;-:.:it I'i i>J. itist 1* a tosiM. be (x,3)i «md(b tK! rt 1 -si d e ta cXi 'j-^^jnt ; there ysrieble letter in (b u a) | i, <;flti be ,^)i''^ of repl^clcxg tvo occtirrencHS of a -.srl^bie letter -wblcb J I^C^.)) ^- ... .,- (s.,2V); U,2)); t'aea H(a) la 2, cf/aipcfct-. t^?o t, > repi:.. .. -^vorsicsi ccsKJOnsnt GetachrK'at or .1 v., th<?ro they t-irigle orlglaaUy vere contained eitaer both or bach in b. In other terras, part la 1 j_gt5(^' '^"^" operata<:a T.'ie.Gsrves the rtcrcattca^l aistduction cf vGilBbie letters. in un proye the foll'^rinp- ijst foina '^a-:a *hBi ficn (c tiJteir^s p-^ W.3.)'iM\>} - J ia I bU >i^b.! (3) (6! Prciof If c ioes not ' oc':urT£ticafi r:<:jni.^lD of V'^ria^\e the vbeoxeffi is tru.e beca'iae, for cil foras 0-;i';'---jse.. merea^/ i-ihc-iild Jtleo'ic--,! iti Al ocoitrenctt' of variAblir both Let v be such c--ia?ts.. letter (x.. j^'-tA c'vnonlca.i occvijrrence C4 ''5.> A • -^(S.) £_* ^ and ':,. ' aay of ' /,. ybich is c-btaS.nea .letter (x,^). euch th^t 4-='-^'''^' sad e^ca occurrence of arxy other + ^(s.i)> ^.-th e-ach of 'fz/'-rt-V >.- C^.,l>.) puttfiif: tbe right i^^sb^ar of (6), v Is first; .replaced by h t-be then each occurrenc-i: c-f retiiBC8ES:nt is T«:pl6c-ed in^ on "f'o.othiT »:yr c<.) ^ T-xn.cticn by not, k.> because tbey j.oGic.el coaipon?j;at (x, M(6) coise , k let,''^er - .Mf«) Xq fchl.3 frca the -- (x^ aij., «_. Ix: co;?,- , auj k) yithlii tiiis Ms)) or by c^sse ^'? '.« l6-l";£r ^r-r-'-yh'i t«y t.h» left ceciber cf (6), b^ of b by rep'Uclne corrfionear, • ^-ly £ Trcjia .lettei^Sj, oc-c^rrefii*©, >.iu .','- - "" '' V is replac!?:d by the i-' tae - be proY^id by shovjcLg that sucn repUcesx^nte are ' 'th^ vartsfcie :-'j' ''c'^" the tvo srembers of (6) are both cVr-ained yeplfjicl;*^; tbeori^K d^, li^i:•.l:<^^^ *i, , the resulted sense actirai tflken on ftepend-are obviousl; tiie efiuie 0.8- data, ^^jhicb are siirrpiy different3.y located %jhen the ectioa la taken, Consiclcr ncv the cr^se i,>K(b). In this case, in ths lerb Bcncsr of (6).v ±s replaced by that is by (x, x~M(q) -s- E(b) i- (x, oi-:ier placed by (x, i -H(b) + j a)), H(a)-K(r.)), vhile in order to com- pute the i-ight maabex of (5) it is firct replaced by n(b)), to compute(a| b)j to coispute i-M(b|a) + H(b then, becaiice of E(b)-M(a) + H(a))o identical, and the theorea is thus proved. ('4-), (x, i-M(b) + it is finally re- These re.pls cements are of da!:o ^co-s Tti<? . ahilit-y to de-tvii;: llie rs,.s\-^ac.e • ;pi>t.t;«nce preserved "c goes iVir of CiSc^icnttient beyond the ,: de^so-b- n--2tu.rft of t,tj!^ is yi*? uitJ by ,5 propertY -i t-t^j .-^ic i-r^fj? • abrftrKci ot-j>er / th'3 defiiiifcion For ir, of j-.ts detachEsnt opGrarion. pj^scticsl purpocjs^ ijjcat iisefiii •vfiien (?),, in this particulor theory, detachtrien'c iiectlon i^J.ia sati^sfied,, Gr?(; its sssoclativity iB utilized oaly under the hypotheses of taeorerii 2, yhich gJ.co allo-r foi' a trivial proof. pletensss, thic- section t'iGnt i;; devoted to defirdn^ that is^ to proving the osslc detsch- rollo-;d.rj.g Theorem 1 (/issocistivit.y Theoi-eB/ (c \(£;n)) Let r Proof: "dc =. If a, (x;t;!-3), l)-j corsias, Q(H(e)). e, vnoss firt>t M(e) aad the fQllcifing ?or i''*M(s), ^•^^S^5.''"'^"^^-£^"*'i)'' denote the &re rha cononical e3.eEf;uts Stva Yrill bi; (-) sequence of forEG, separ- -the Sequences ottsined e'' QX^^) separated by ccnaes ec/ii- the elenronts of the saqusucs coGse«uent-JS.yj,tha called infiaite forcus and and let (x,n3)>-».".'.»^^'.-^ be e fors, end let e' denote pcnauts of aad c sre foriss, theii (1) g uon-ncgstive Integer;, (x,t;rl), £ o ((cl b) '8) iafiGiLbe eequeace of vsriJ^ble ler,tsr3j ated r-h-is ecu:- op€r.3tion and t6 proving ita associ.:5tivity in tlis cost general C5ce, Lefc section lo, for the scks of Hcr^'everj i"th eleu--eut. of e,^ is aCTwc like e- vlll be fro.-a called the iafiuits extsusjjon yne forc;'ili25tion oC this concept csn ijr:sediately bo obtained^ for exr^cple., setii.-cricGS by imljGdding iiafiaite foiT^- of cox-ks obtnincd by replscj.ng "finite" in definition h, eectlcn i.2» 3.nto t:ue class of inf inite "f.ijiite oi- itifinite" 'j-i;e for concept of csrionicci ) ulstcaat. of Lle.r) ififial-)-,e fomsc I»et new g be 3 Ri£, r) can ana. for;s cz'' non-nesative Jnfcegor i. aa Inrjnito fona =: also i'-ieni ?v.firit.y 3.et 3(/.;) l/^ of z 'Sncl aenote ^ tb.a fcra ical contract.I.cns sud vi.ll ba called glrnllar, ddcI denoted cJas£es of can be .represented by cciKKon coatraetion elti\..::r £.'iri?!S£-%,5}'l' e/^-'i?, is reflexive, slsi- eqvii.vsieiice binder sucli relr^tion os! vriil ;i^ 5}S?X_£!^^?5SS:'^ °^ S° t-b.tE The conxponen.t£ of a term of theii' ECHb^i^s. differ by the number of trailed be called trailed ^'^^ simili:;- fores can on'iy corrponentf?.., If B «od b sre c ovitra cted forsy^; t.h;'2t is, co!::poneats, then (bja) Is also coatractadc If n, b c are foxtis Eucii .lud a-iie eorrraarativs the comaon Infinite oxtenstcn or H which are not also coioponents '^'^' the SEaliesi b bave iuGntloal Infinite exteuslon::^, they have Gti;! relstlop. of fcrrrs, and transit lip's, to Q(I(£,1) will feen call cont-ractlo a If tvo foruS a ajicl e>rf-,end-?;'j such that. R{g, 1) V7e ?iiT)ediat«JLy l>-; that »3y^b, for-if.s Mltbout trailed th»n anol Kow let c and d b-:- like .t..i (c •-" ;•-?; tu;iax:td infinj.ts foria. Tee per'^xai dctacbrjent id; Ip— ijecT-lon .!..> t'ct rori-na, ence that the litaitatlon (2), oecxion l.;?, v.' .ii roe C"ily c:,jiei- doee not apply in tliizi « -23- of ini'lnitK forcis Vax-llal. detGeiuiieji^ cjiiO. :is nor. GlvmyG defined; but alco evj.deatly SGSCciative, as only .van by repaatiag tea first mii.' of Theorem 2, aeotion 1 more, for Ttiea, for say - £. -.; b and £ or trailed coeDroonentSy tiiat is, tbot thsy In order to do so, 3, : ^r aov prove that the two njembsrs of (5) have the sm-al- D.i«.ubsr :l'-i "nd b, forrss a t'arc~.Q Fiirther- by contrscting, Eenc-s, He ^vo ir." be proved b, c. (,'v vs denote .let us call arid 2.et a s?"-, sm sa-ne eqxial. s eoiistant viaicb never ocovcs V- and C" the nc^r form? ob- XBinQd by substituting for each trailed coErpcnent, sey (x^i), of a, b or (a, Tac: fCiT^ the forni respe'Ct.l-<relirj ^, bi-- £--^, for s, b and (?.,i)). end (6) are ccntr.Tcted, c*- respectively ^In c, contracted forsES .la !>), and;, bj rapJ^clD^j theni ibe sine-?? (^ \(^ I e^) )=:((£*[ b<*)\ c;^) Let us now replace i^^jj^ ror all corresponding Because of the waya \6\ coAtaiued in %7), 3T"plf>cen:<:rnt (a^ (feta)) detnil3ffient of contracted^ ve obtain traa (?) foraii? of the typ'? ciiosea,, this trciisforss the lei^ and rj.j^t meraber of (7) into ^^ is conrp3.etGly (Cslb) proved j e), respectivalyj hsnce (i)^ and the theorea .24- Keffisrk'^^TIie in tha.s section^ vhich is bosed cii sa isoiaorphlsm,, Is but hea the dlBacrrantaz^ oi* isjpi.i.cltly re<^uiring sl!x;ple i proof of the fisscci-stivlty theorem given tho por.tuis^-e of irbe denufoerabxy markS; that !:;ODy exir;tsnca cf a space- of setrs of is., r»e-s of pc^e; f'-^n' postulate cauuot be represented in any automaton, This sr^d i consequerniy hoicts is iisbedded order to ."L^uch priori think one; co-.jld 3 tbst. assooiativSty only provided that the flsnu"icrabls space of forms j.a sb.o':o an appropriate Gp;5ce of p:>wsr ^ . In that asBOciativity holds infiepeaaearly of riD-beddin^s abova postulate- one should prove it independeritiy of tho v:iiat is. fanite of asaociativity.. fe,llin/5 j\ one shou).d give a proof in the Hove>'er, withia the ccope of this this logical poiat not ^•rork, it •ifil]. not here be the object of further elaboration. Rarasrk 2i Let.A be the erspty e:;q>rsssioa •., which can be represontod, for exiicple. by (x.1), vhtch in sirailar to ix.] Tiisn for aliforaiB a and Ir. other vordo, if vs consider ths; faasily equivalence by slBllarity of forms, theri; operation Induced by detaehfiient, this of ail oinsaes of under the biriary fataJi.ly having the class of eciuivalence offt as ualt left end right. See Clifford and Preston, j JQ & Gemj.sroup elet:eaf . both Let UG nssccinte to each forci e_ sn inocgei- i2£!££S£k2^1 ^^£) cuch tbsv n(a)2i K(a) (1) Faenovsr a f oi^ n ic cevly iritrocaicod parar^cter, this one P.»EiL-;iinG ir> tnlzezi the notaticn unsd in lot c-et2ch~cnt;, xeplnrSnr; for (:£,i^ - H(s) i-is r;£ctio.a I.5 to dsfino partial consldar the nc? fora ootainsd ^roa (l- r^k), }r_„. -.fitbcivo specif^jring 5.tG to do £(2) tl^.e n-bv K(a)) if .;. (2) or else the 1 -th canonical ccnTPon^rit a^ diffara frca (b in (b u£-.r fcrtTi ii: of c;. ^irhis ne-i? for^n a) only by the variabla letters sr-tififj^lGg (2)^ ^ in thio c2se have o siiuscript vov'-lc brrvc ruis by variable Isttsr 4^M(o), -ijhlch 1> 5 _.£) -t.iaich exceeds the one tbsy by 7l(3)-n(s}. called ^arcpotria r'a.yticj.^^^d^ f rc-a 3 H-ith paracstor H(o) cad denotea ^ b- f^ud Hjb K(b) f.^ ^ G jlR defined as M(g) .. %) (3). i=he.csGO.nio.tivity of partilal dctach'^ont of for-as ca;i bs eicfcecdsd to parfiusstric pr^rtial dGtach'.r.'5at cf forms- th-as obt3inj.as xhc H(b) ^ M(£) 11(c) ?^. :.:(b) Proof: Can bo cbtaine<3 by grrciixloGlly replaclQ;^ i^ence of K aa occvrrcncG of H in An undocoiqposa&le of- a occia'A-eace a, of lovel for;n ir:3.r;;i oc/cr.:", ^1, vxx\ ^.-cvdc- There casiaot be in called aortal. statins fc'^^'t definition 1 or 2^ £ tnu^st be the yiel.ci t'-.n fi'i'st v.. <.-. cxje ijjarlcs ..w.^v.^l of a of a clcstd pai-cnthssrls. at nsptn CK buccuse dapth fos-m s. Its Q ^s a foi-m; csnnot be aa of copsas. lest st-sts- ccci!i-r.':uce of cecticn 1.2, bscaxjse in the first esse stotSEont caist e^ Sirnllsrly^ the 3^Gt . cocv.ri'snca ot and in the soconcl one it O.'herefora tbifs 'cg The the one of vaich Kunt exist b-accusQ a occu.n'cnces of woiud 1-T32distely have level 8^=, ccch cccur- aave to bo ths oscun'encs of depth Consider a structural pi-oof r;:;jnt, .io a v.-ould not bs unaocOLqiosoble cccuiTcncs of Q E'nrk in thii! 1 .fcru* section 1.5- 2;, ia a nors-al i'ora o K.ust an cpsn porant-hosis- otheryloe hns ?LSvoi tbeoresi! vrcu3.cx c-J.thsr £ vould ba decoirposable. be an occuii'f^nce of dcf iciiticn 3, section 1.2, atatins that a is a form bscanse it results froc the enclcr-iji-e in pax'sathesec of anorthsr fora e*'.Cont.cq.uontly, if one ^21- i!?fficve£? tho a rtorcTil iirlticil fo)-tn open and the a he vi3..L x pee}.liv|^ and _e*. parentheses !i'^hlB ic called Interior a"-* . The r.oneopt of pariaeti'lc parti-ai Let f-icatloa-; fi4."Y j i=1^2. oK^ let e bo ?3nother form' ouch it M(e c.c?spoaeiati'. whei'e £. e. clC'sed p«irent;hcr7es fron: vvd anat.her form romovsl opersitica is called of a I'in.nl of e are nontiai. needs ) of va.lvi.e3 and Hlg. ).''M(e, and = M i^ad such iiiat ail can"*n-Lc;Dl ConaidKr the forte c>c<-arTC!nces ), _i be msiy snd It csa happen, for up n^rt conjpsct, but one, that If thic happens Il{«. )^- ;.I(e)v then tha 5-th coaponenv; of ths of e variable letter (x, foivr; occui-rlna: in g^. Let nov e, be such that R{^.) , i 5^ contaioB H(e )il) wh.ich is generst«G by cb.sngin^ the subscript of the variabie letter thr/t e JusTi- G-Jnif: foncs. c;f clenotes the? -Jiiterlor cf the 1-th eanopical corapoaent of In geaetal, a. to all aet,;jchr.-«r t be a oequence (x, M(e^)-i-l) - HCe), aaS assuroe i3 als?o compact.. 'Ihe J-th concponeat of (j) st.lll contains oc-cirrreiicc;; of the variable lsttc^' (x, H{e^. )(-i); has a ccmple-cely differenl origin, bcrv^ausc fxiflted ia e^. that Iliia e',casple chtXiis whxch, hovever-;, such occvxrenzes pre- i'orms g., are detached from the Interior of the correspoucling cocrponentfi of unother fora £, then the globcl notatjonsl distiaction of vsri-sble iettero c.n be no longer preser-zed. / Hcvevcr, If (5) i« replaced by |H{j;) V / JH(e.) r / | H(e) s • 19^: Is .5 ^'^T lisv int7"v>dur.ecl bv ]^ev,'eiJ. end c-squec' Out of -i :; -Mti; -3- (the free: storagf; vanl- list. as soon cs their ) to further proceuslng cut sutotj^vicaily by the ahstrsct rcmpufcer. iL'emory Irt'elc- nteatr, becrcroe rv; !'5ainf:enanra c.r t.his po«I is carried The perceritsge «f space devoted to orgsniaationa i overhead is thus constanii with respect to she Ifcngth of the eggregat.e^ stored there. A3 it will be seen in the sequel, slso the percenvage of time devored tc overhecd cperatioife, sur.h as addiessiog. Is alsc? constent vlth respect to the length of the aggregates operated upon. st-ant; ratio of overhsad space and tittse featuf? of thio Zits^-roct computer, and This con- is an Iniportaat pt?cuilar aspects of its design tr^xiy have been. devJsed in order to provide it -with this featvire. The study of coaputation ^chesei; vhex'o the ratio betveen average organisationel. overheEU in -"p-^.ce or lima snd rsspectively^ increasei* and tends to I when space or time, "ot3?i. t:he iengch o.r the comp3.exity of the inforc!8tion to be processed iticreoses, rady have 3 cGi-toin tGetbeffistical interest but. cannot ....'i:.!?ibly ;5ndlcstioas for the euveiaceEent, of the coisrputation give good ''"-' t hod ology. In fsot:, Khlie a coastsnt ovarhead I'atio^ even very high, potent-lally be reduced by Gkillfui tailoring, esse for overhead x*ar,tos This iG^ in ossenoe, not bounded abo'/t:-' by cea this is not the a nu>uber <^» lo the engie fro^a which the desigi'; of the memory orgeiiizction of this abstract computer should be viewed. For '. >•«! ^ oc re;.oec; ^- )"£;> Let; i '••«!=>•, denote this n, -£p secUon of S I:-L'iS.^^£lLii^ ^ oaloiiprirv;; fleifi of to '?' ^^' vho-re. if The Ini-ttal ac' -i^'rh word. If bnfh n fhs n, -n._, ^A:> pqI -i. n - 1 one. ^'-i^^^-' ••:= J^-'-cr .13 . - '' Tne eddress of no c-r vi]/' tnp. . ; .:< ^ of v of S -s -, on vtjetber h- tn?" :ng on -^r 5cldre;i. deper.dlnfi; u, hj letber or £-i'"IJr 3. aXI voi-d? of 3 no; '>f the contents of the liglit 1. deper .-iv-iii v vl- consls-f-lng zepla-^'d. • ^ or the cnc ;, n. the {n.-l)- (n^-rl)-th woifi or by e 0, n. >• I, il^-t ^ -if.- . o?- rv. ce coiiveied c:' s^y ^i<i . z-idr esses of t.>:- -. -na v. • u, ,- referring those cases wlisia xae uouCl.;- v.. oiid '/^ ., , «r« iv. gdaresa se ction anr I'rcta t^'!nft •* -'•nc '•. Ce.r-.i.:.;i need =- ttae n;^'*ih ".' 1A£ t-?; by .ha •. invc'i'-ed :>i2ich ones ej:>ictly r«feren- s perwHrient proceisseci wx" %he -vj flrs-fe address of c-c >;f nhe li:^-i '•: 'i-- :! •>:' a . : v'll'i .y^jrci 11 ^lo;^ h^nve chrae fl^lci^, displayed diBc.u.r,r,ed. • -- la - tlie sequel) -- -^ ; abfaira Ti;e 1.S be -- - 'r--- List S, a word cabled eoni.rol word v^-111 c-f bf=; vbich se*?. Igrjc-d tc .iv, liiis , .'^:....-, ^i. .rai vord tiae life" • >• • •; .-i:;.' , d l.n odd.T' i03 atains s ' - . Section S.g Let S be o f-'MP;'-<^iS^^,._l^.-L!L- « llsir, 3c;w,--eg?.te ar.o -'^n Let. 3: , • i^si, 2„, . ,1,'. a_)) Ir. S8i.d the t-p + L(s) of the \n n-'J'i^ to 'oi? ii-ora - i! .1<^' ' , ^' ^i - located In r-htr centre of ri.f: o~;-;-e-c;te ". 3, •. •''. • •^- jip*eg«tes ara • - j,:i -^ - • tD.e :;'.x.;:: -^'^rd. it \a tak-u der*nir:;x? ^^^e -.?:' • . In listo in t-he rever-se ord?r, e etc. -, ' r csjd fj.t.i.ocar.fid inp ::.-3t ' vr- • - v^.- .-currcinc:^ ': £ cf bs v-ad(5res3 aJlcrexed reacs of h^';' r>gllcc3tc^'^. of that ?aica ] denote vhe J.~th occurrence of a rjark in £, Tf for ail i iihe nsi-k occi fi.sjlrl s positive iareger, r; n + K(3) : • vhe esse of occiirr^ness of pgren fixes es. «;cteasicn shouJ ;..: r>r or rlr^ht- or ir • cioseci c-;/c. left., f . ',:;;n;'r xer."r..'->r'v.lvp!i ^^^ peadlng oa £.. 1 a), xf -^aeoVier it is o y. of q,. In ;? 3n Ui, deFtii is -l or +1^ , ..'v.. '^'^(£~j ... LV^ (ja^_, ,a), depend li^^ c-losed pareniibecis. de- closed or open psrenthee .-ft de-pth is asfiiy^a '.n If It >_ -r ,-r i) or not a^ Conversely, D.(e. /,,,8) i: 1"^ ;-j^_,..=2;-:I. either r^ (ij.i'S.' "^s v?r , : th-" '^rcvTTi^nco '^'^ cf s - 0. ac /I D a '.'f , 3 ', •>!> and occurrence of a tie, .'.a .. , , 3 for ) . L< 8 ) , ,t 5 D^^.s ^^ ., of aa cpen parenthesis in be cccurrsac«s of depr.h right of Let. £ in d, sad -^ i rf ••'••' In aatl^ateaf ;3 ft' . . laot-e £ contaHas •"• to r'.:3aal is cai.lect :i --rv.-o i it:i-t. Then there a. ^-^^i^; igbtrsost esse vhere v.he a. t.--; „ OCiienj.ise, .3., then a, the Inl t l.a 1 icti . is an crifur- Is scsii .:-!<::: ' be c^jlle'l vi'i I coocj^js fce ^., 'rr?' the If chere ^re in a and to r,he pcciinrencee of 3 £ to -the of 3,'3ft p.. l/uc Evate cf 2 For ey^mpie, in .he rcate of / 'he "ccurror.-:"'' ., t.he .le :. . .. l.he cTjste .- ..psn t; of dsp'M 0. ox s, Otherrfitie, the roats ^-S-*^ ; ''U psr»^n-fh. 'M a, thea, if'^LOtie exit. parentheses at depth ., d, Notice that the snticnot^r of 3 not necessarily a. form: in -. occuxi then right-ssost of them 1g o-;- ajvays Is SDld to be la^ .cence cf dflplii d cf in <5^?2tidlne he sa oci-urrence of <_. -••''' , is the OKate of If a . < iefv,moK( £ '.> cuasas cf theoi is zhe fsate of a lefj.n^'.^t let • rence at dapth d of a ccHUca In a. uciKL'ited y£ . *»:;? c3'"S'. us extend this concept cf che e^ depth of ccc vi-Tiences Ci mark£ io rlg,ht. t'be porc-iel forsiS can never be negative, d_ ^ or D^; , e^) re'ip'^ct.U'e .y, aegata-v?- After reQiadiDg tbat deptb open p??reuUr?su>, o.^ left and right deptbi- thus deflnr.'d a form, tie-y^r i-i. ci.c2t.-ci . . the icate of the second occur rc-^rice of a ccsKaa is cotr.rau. rence cf the xeiice oi a Tac initi^i mate of tblo form is The ccmts. parHnthrjais is of en ffieans wjile cornffia, ayte it.£. li- open porentheaifi, similar arGU!;;f.vat one used. to prove the canon- t,D tho' dec imposition tb.eorera one can easily prove that, the aggregate icjiLl consistiog of p.n ta.? first occux-- i/ae the cccu/rence of the ciOBed fintimiste of oecond oce.m'reuc-e cf a -cas the oc'urrcncs of Sy pa rant ties *, valle the first occurrence of a closf^id is iinfflu'ed. co-irra occur- i:he " a3.1 ozc\o:retiC:ei>' occurr'enr:e of g piecetiins -jn mark of marks ia a foiTi i.ncliided between. esciusivc of «r.d its r^vte. or ext-reicea, of e corisa, sre forais. xizisoted occuri'ence a-^ilooai'ed ^b? L-:^ Gad V'Crd of " in the iiat S vllb connrol i^, c-Uui.HOae ii^ •.' the :rA ccc\irr'.n:; ^:;i:' fU';'- :t.c- tii, ;;3r-?r!Wiesj.G, - fi?ld t))/? is ;n- : n ^ . . sddr^:- ; c-:e • (n-.' - fcfit-jd, a: rif the ?';;>'. if n .,.-:;,.». sup;/ -.1 • . . . jrd the address yoovo! the !:ae c;orrtrol aJ-.S),, r^^t? '^f sddreGU cf word address ia conta?^ned ia a B, suppose .further of S ccntfiios the Initial if a is inli..i.elly uoEiQtcd, ' Lia)-I.^ . field of tr.c carrying the word of S o:'. ^^ xurni^t^d. vord of S or cne one of the control vcrd of --.r; depcnrling an v.acrhsr or r >/nGt ';ronds tc : or if tiae address if it exist, ?:, -^h ' word of S j;.\£)-i^N;S), LJp'.icxa'L vord assoi*.- . > J of tilt, , Lu^', dofti the eavae ling » nisLed i^^ccurr^^nce ' iuc '.e ' .. tt'> • iaroi <? fi'j-av:; :' . occurrence of a . .; f5x-t.rf n*: waere of a caarK after tae other. Me • ''tr car-ar-!- . Uxe corn ;:rejice 9.. *?, vpt^rn.- . -.1 ^rk While t;;-;- throuj^h the proportioutil tc the d-^pth of euch the leri-(.'': .{' th^' r.j^ai Jri^'Viivefl. ' .• 1. of Y -ailaed by •'' c. tiie £\\*.+ i........ f;blp i. .„.. .. l'(ir i-i 'it-ytrfict r3T i . J dettcrisents el'ficieatly of ovej-heati ocerailoa:J due ;ter Is uidetiendent: of the & ii „ Is? whtlP! beyond 3:.y wou'.d Itapiy a ratio . ,. -^ v.iuptious ox" the also be noticed l.n<. --^ing Xu the ahftrsct , -t < sovj dej.:iirri of tbe abBtrfica ^iooputtr. while pbyslcei threading moves that., mx-,u i.ac uiiiy on which • K-h a '.£ the iy as «lap. alng, titrorcly all-, w-, tJtire^d,i Lig, .iple< for; -pfv^'e" r.;f- directly ^nd thus ler- 'i;<aTe»K«ites i quite touiputer uf logisal xv_c . tt fietsfti. fiximnr. a«cnje«t^i >6tCHi thrRUdli'iR L,ii5 rc'-r.fl , • itDbedded In 11 sts^ lop exception of when occaxVoatS-^ '- ';'.?red. ''As csl c.lu' previoaaly said, wordb ol mesory iree fleldc, :>f vhlcb th« central otr-i >ibr;' it i;i..Cl , .tea, the cidrccs of the ii-al list; whic±i ua3 subilut or S conststine? ;?:. r.)p uf tr.; :£ bot?:i rse icg.l':;-3i libt. defined to consist pny^lcal threadlag, j'der, is that and toa end i9- phjrei'cgX threaa.ing ic j fcr j The units ojT lufoxuv^.ticxi the beginning for Icgioal thresdiogc of vhich the abotract ccitrputer oper- stea are towjS^A t-uelr canonical coGiponontp,, not Earks. and vh^n j cancnicei to of a fcna £ icdbedded in a rrparsted upon the i-th of thea ia found b=> its £».lnri? £:yst'?in and ccirjfionenos '-'113 of .rjgh-ctiicst occirrenca cf tbft abstr'^ct should t.bini; y ir.^ri: is tr l.;'/;1cyp "^^ ^, of a logical list in ...-"^.-e, -cercis ;"• .irv? imasd lately, oomputer Is based on iogicni _a lii^: Th^ addressing thi'e'uiJ.ng, Df a list or lists of lists, etc. linked by the logical tJireediag rather thea in terias of a list of vx)rds linked by physicel tnresdins^ i-.ole T"ce purpose of -0^:701091 threading is to achieve maxitBum utiii- ^aticn of pbysicsl storage, and the reason why it goas bacln^rd,? j j j vith rep.peoT. to logical threeding caiy dep??ads on the s'xie of "peratlon of the absiract computer vhich, ss it will be explained in chapter 3, must read the fonas backvards in order to e-i/gluate them. I Iji the metalsnguage the conf^nts of the top pcintsr of logical lists vill altrays be displayed on a Una at the end, rseparafced from the conic at s of the 'rords of the list by 3 facriaontaX ruieo In the to as- sei} isl^ s ll8t oxhei' physical XlBt, 3truc!;ui-ed \hs.i::L a logicel list vill be rcferre Physical lists are not suii.able to carry inforxstion such ae partial fomis^ and th-sir main usage- is connected with storing and sddresGing in sequence marks, tk inly constants ^ 20- Under the -aijtsuEptict" ca-ttnp; nssrks ari^e bb-rraJd is origlualLy 3is far ?ii? In fgc-tv concerned.. ail of storage available for ^ilo- tbfil, l:i the free atcrRge ilst, iio proTjleras the n;s;intenanoe of pbysica', threadjag is adclltiona, secliioas and re3:inDder? de-scribed abcvs are sii operstions waicii pres-rirve physical vhyeadini-;. this is not the cex-fe dons .Mouut it. Ihe so3.ve. ta-is lis?^ U, sequenctxig rsl.L'?a It dl scusoed lu ttiis section 3j.1gws to I r^-c- e-JCh form.';; .stsply iriarks, but. Utbedded Jin logipai Hot Thus def a ri.ed .is cperailcQ of the simple pbysi-t-ai :? Taclts^ foi^ra in certaia semi. c-an referred to ee 6evlc.es., L? of in BOG3etin?.^p con5pu-t;er3 -conventional compuTtjrs.. be phya.lcal.ly addressed . p-^r- ts-m vbicb era preRent- In VTograa'2>ed are lists of Erarks, not of struotured fore ij.st %n a;jst prcgraa corapiier-3 for eoa.ven-sion.al In wired :in list.. sectiou is at sil similar co the one of celled puah dovn :Uats or forra^; that; &-.• c^n bs expeptlon-aily used sJjso for adcire.ssing the allocation of Eai-ks into a pbyalcQJ. t'uis S enocber Xiivc An glgoritbin to produce the "U'Ricsl t.areadlng of pu.rpo3e8. 'ibs icgicai surh thv^t the Itxgical iteia? of S. axQ nor aggregace^ phj?sic;al thrS'Stiing tiJ&l cf loglcsi tareadlrjgj, ualetiS somecaiag is scherc*5 problem by aaeo'i'jeting to slJxvcated in But ijif ortcat 3 •?n, and Such Ii8*:8 and thsre- On the other bend, the IqqiqhI lists used by thia ahctmct computer are a taore general concept, for waich there is tio intiii.tive equi vs.'.ent in ocnveiii Icnal £>enil-conveni;ic-a«3l mach.tnes .. o.r Let a be a ptjrclal form cmd a^ t;he i-th ocemveace froai the right of a r^^Tk ma, Tae fir^t chins to do is t.^ devAse n .im^i^ ''^' ' fcr aigorith^. assccioting to each its rigat deptia. For £^ tbis purpose, one u^xl^ze^ o sequsnre b^, and 5 sequence c f j=o„l. ... t,(a)) of nunbr^v;. of trutii values defined as foilcws: /^i-j k-i a^ la the occurrence =f a closed VGi'^vt'iiisis ^ ^* v-iienerer " '•• ''^^"'^ver £,__ L-J I :-ia& the value f b^_^ ctherTrlsc; •^fblle ^^ I^^^ _ C% wlienevsr 3^ is vae o-cur-renee of an open Daren^h»«i \ otasrvise / purpose of the definitions is to be able, for ail ^he integer D^(aj,a), vhich equals b inln-s oo a^ i.'- i:/; and a i, to con)pute or the basi^ of Infox^ation si one consider the prcbJem of proceeding fron: tne parciai f ora a to seneratlns a losicsl list S with top poirrters.,and control vcrd L, such that H(S) . !.(.), in vta.h a it ^-inibeddod. The b^sic tool for this operation is s list U, vhich initially con^iste of Jua, one vcrd, containing In Ite centre field the address of list S is Inin.^Uy "^ -'^"^_o^ address of e Q-Ust, conssquenoly botlJ'^,^ ^-^.Tiie ^.^., The and algorithm consists of L{a) steps each " , of whlcb stflrla with the ccmput-anion of b^ to cf S of rue. '^nd replacejiJ-rni; m th^? xaarli c.f,^£^ by occurri'ng la ^^'^ 2, tiii« Sj-. coatento p.r'eviuus 1:he ':iad '^^^ addition the inrpji<r:8 the left f Je.ld of -^f the ccnlro? wortl cf tne free K'tora^ llan, La? u d'-^note the —J nc--j w.^rdr, word of .1-tti i- cfarry.lng n; _i i~lh vord of S in its rlfjht field Is 3dd«d to If a camni^, <5^ is ra. vord cf r.evr i<?* catryin^ ^ v?ora, le placed u-ho~e iddrfcs S, replaced hyji^ is u ,i.n t.he i.ft^ u^ U ts an If m. word i--tb such "h-st'/s, addre^^s; t.o free ttoragev the end cjf flnall^v,, the fltsf j a^ the performsnce cf the i-iiab^dcied a cpen parer;i:he£i.s,;/i then. is 3 ciused parenthesis, of U vorri s- In. it V p^ivtiai express,! nn a* is pis ceo tiavirifj 6b u of U are eraof^d and gtveri besok Igor it he, U cc-'nt-alne -Is of occurs: eticeB of open th*». T'hl& stid closed above logi'?«l list ' S,- At takeuc as oany vords to another logical list S rar^u-vting to the end of u,, If ^ is the a ^ s iu Its rlgiit f1.#]d S; vfordc- nu!i;ber coosna. 'Ji u, t.-f Consider now the problem of proceeding froia vlvh is; Xa all other esses no f^arther miction ss the difference between the of the ^ clostvd par-cthpe-is, ^'^ H.s c^M<^ is placed inxo the right fieid of the liS t,be its ceatvp field and^^So^- right fleid of the &ii3ile3r. pOis.ltlve iategei" tbr^n, i*"?? wbil'*. la added to tiie b«gina.Lr.tg of Into ; Sc3« h'Sgiuniug of Uo the rigbi: field ct thf! _{-tb int.-- iScr(^£o* .- is « oloaed pargnrb&ess, if o, its centre field and the address «^ .la , Tben. IJ, froni operation csn be adding •?-3- eaaily performed tbac the statuo of U at the end of px-ov.ic?.eu the generation of 3, the iatec^r ^t U alnvoj one, and ubs tra^h value t. nu ,• •, ;iB a ;" ^ .^ . viitch is the .length of $ which id oJosed caren'Vhesis, sre avaiiahle™ In iff the f-act, ganerctsd Just by continuing xhe operatioa of forcing S LU)-'t-h Btsp, C'jiisideririg a" a sxtGnsion of -r, S' can be the 'fceyoad £> This proceQur'2 alicws the relevance to the ooexatians of any [ioglcei S cf three items, liitfc vhich ot, e9-:t nam'sly the ilst U step conteln the. for ail coaipoLmd of b and t. vhlch, vord of it^.-iOry, is called find t right depth h. and the constant t., Ll8t U Is called as6ccfer<edl3st of respect iv.?3y. 8 rise tbe registers b pxir-pcses; S, vhile the cen bs pieced In the che Rtsaociated depth re gi ster of S and denoned 3^, The above bestc prcced'jxe csn ba trivially ext-^eadcd n-iiBbedding to n + L(a) of par: iel .fores a into logicel .lists S such that K^S) Fx'om this point on, if s capital Roasn character £ur.H2rscript;g danotet:- a liKt, The Byir^bolic example. and c., ^ list, an. if i iateg«r sixbscript i vill be denoted 0, cr its control word if :l^- je \?sed to identify the top pointer. subscript If S is a list, cr vlthout the corresponding iov'sr case charocter vita the same axiperscripte end the l-th word'Orf thao vrith s then ~Q its top pointer.. - 1. 1'3 its control vncd, s^. -5 its- For fifth vorri • M at log - wtii be T^.ert' wi whic:b syitT-ic cr.rjxpurtr It; for Tiiis .. j^' .1. addUlcn typjfcsi vriy i,-hA beaed m for ot*^ci Crtidltlo riti '.'-f grk'r to addition is irrtrojuced ov»»rasl pf'fi::leacy tiiii^isr put.!(i/lL,U,y - as will prc-isXeraaj, So f^r, aot beio^ yet c.f •-l.y - ailc.-v-d ^'l con*xs"Cing of tJii^; b-gc'cy-arj the roiidltu-nsi- aarli^ do Sfj Let a .Jfi 3 pan 13.1 from the right th« rj^^lt tb5V ^ a Ito i>- . d«?p^ cf 1-ti^ Ui-- -soraputatioxi) • f . th«? fQ.r^ ic 1:tts second it, ocyurrt!n<;«!S .'f -e^;«ry v.;. .,.,-. j r:;-rau <> \i-i.-^ h.. a:--rk':c;; 4 «s . , ; i ' i^^. >. v i-rp .-ccurr-^tice U'S cmtk occ^j,rv:;j !r. 'vht; u ttift 75s?r'_ .If tn^ a . *.£< <r -; ^nd . . coinjiis ttit-fce.r Ir .'^i the however, ar? of l.tttle cr no relc.-rsnce to For examjvle, t&e oete of the occiirre-'ce of ocf.utren'. -' .• i/.-Jij the iei'^ •• , au-j s^ .if 5','f in pcT.st.lcs.w, - n-:.t, 'c' -urieticvii^ cii»=piier 3' fhis •sdalticcy - acvi wccur?? free in- "ororsa rti'-jf/ing aii.vsv cw^ac'-rv.i i^•t.' tw? to stior. Ic-glc-s.'! »5i-dff r.o corufiiete. .In Infers-'?*? .j"''"^ ia exyi'.aiaeci. ie reth-^r awkwvjrci to preswr.f. witb- W -.-^rder iti nco-J.nhereot, uaootu- '--'^r:iat/s • J.r.^- of the abstract sdrJretis.lruj, c-f thr^oci U'^c:'.'n tirie ^'f or^ ' a Qf ^mbe be icc^d two :>ntrol rx'^^i v re ^atJlng the i-\h -'-.tii^ li :.., o iv tie ojj' cont?.1j23 In its right field the addiess oi cnw i,-vLi vvrO. th£ of list S, vhile the first one contains in Its right field the depth B„ x-ight conra, then, -'i^ = -^y If^^i-'- - b. Of the oceui'j.'.sricr; . and in its cent::? field n £ o^" if octhC' V. of j- b, and()',r," nvA'C'^l iSf"., r- "t-bie -'iTxi h., . . « If a, is a no action is t'^ken. meana that a. is the mate lihose ao.dress 5,sl\ jI . and the action to be t3kon ccnsists of placing the address cf the i-th word of S into the left field of tho '.rord S vhose iiddre^o i3('^,u^j cvf r-emovin^ tba first tvro vords of U' 2-rnE:;jai.nder of U and taeu (that is, rcpl.ncins U by the )" Another posGibillty is that b. -aS^-\} '-'» ~''f '^'^-^'^'^/x'-'^ls' T'-ia cBtse In snslogcus to the first ons, with the cniy difference that e^ is the to bfS mte taken of go Is difference that Finally, orciirrenc;-; eKactly o',^ if neither 'ohe orre 2nd U '.:-f of The action -s J^"^ Injtsad of y^\ of •'•he firet case, vith the only rejilsce o*!! and U"^,, < r6>.£psctivelyc these two coablnetions of conditions is sstiBfisd, D^ is not the mate of anything and no action is taken. The basic difference betveen the operations of niating occiurrences of open parentheses or corcaas on one side end occiirrences cf closed on the ot±<er and }S\ /^^'^ imbedding purposes is that- in the first <f' parentheses., case one should merxorii^e all addrssses of possible cstey and plQce thea vhsn the occui'rence to be rrated is found^ vhile in the necond caee, since the occiirrsncc- of closed parentheses and condition msrko pr»-ct^'J' ; I ! i be:" :;• •? known. ,1. with -^fi. I I J/ ,-"' Date Due 003 ata ito 3 TOfio 3 Toao 003 ata E3t 7-^3 Toao 003 ata i7a 3 S-^ 3 TOaO 003 a^T lib iiiiiiiiiiiiiiiiiiiliiTfliiiniiiiiiiiiiiiiiii n4 3 Toao 003 3 Toao 003 ata eio 3 Toao 003 ata ms 3 loao DD3 a^T mo flba 1^-4 '.^