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LIBRARY OF THE 
 
 UNIVERSITY OF ILLINOIS 
 
 AT URBANA-CHAMPAIGN 
 
 510.84 
 
 r»o. 308-315 
 cop2 
 
The person charging this material is re- 
 sponsible for its return to the library from 
 which it was withdrawn on or before the 
 Latest Date stamped below. 
 
 Theft, mutilation, and underlining of books 
 are reasons for disciplinary action and may 
 result in dismissal from the University. 
 
 UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN 
 
 APR 2 e 1974 
 
 APH 
 
 9 /?ep|i 
 
 L161 — O-1096 
 
Digitized by the Internet Archive 
 in 2013 
 
 http://archive.org/details/nucleolasformals310irwi 
 
3/£) Report No. 310 
 2. 
 
 MJCLEOL AS A FORMAL SYSTEM 
 
 by 
 
 Marek Pawel Irwin- Zarecki 
 
 February 21, 1969 
 
Report No. 310 
 
 NUCLEOL AS A FORMAL SYSTEM 
 
 by 
 
 Marek Pawel Irwin-Zarecki 
 
 February 21, 1969 
 
 Department of Computer Science 
 University of Illinois at Urbana-Champaign 
 Urbana, Illinois 6l801 
 
 *This work was supported in part by the Department of Computer Science at 
 the University of Illinois at Urbana-Champaign, Urbana, Illinois, the 
 National Science Foundation under NSF Grant GJ-217, by BUILD, the project 
 which is sponsoring cooperation on EOL-U between the University of 
 Illinois and the University of Colorado and submitted in partial fulfillment 
 of the requirements for the degree of Master of Science in Computer Science, 
 February 1969 . 
 
Ill 
 
 ACKNOWLEDGMENT 
 
 I would like to express my appreciation to my advisor, 
 Dr. Jurg Nievergelt, Associate Professor of Computer Science and 
 Mathematics, for his guidance and supervision of this thesis. I 
 also gratefully acknowledge the assistance of Dr. Leon Lukaszewicz, 
 Visiting Professor of Computer Science (1966-67) and Director of the 
 
 Institute of Mathematical Machines, Polish Academy of Science. Also, 
 I wish to express my thanks to Mrs. Freda Fischer, Senior Research 
 Programmer, and Mr. John Sidlo, Graduate Research Assistant of the 
 Department of Computer Science. I would like to acknowledge the 
 personnel of the IBM 3^0/75 service area of the Department of 
 Computer Science at the University of Illinois at Urb ana-Champaign 
 for their assistance. 
 
 This work was supported by the Department of Computer 
 Science at the University of Illinois at Urb an a- Champaign, the National 
 Science Foundation under NSF Grant GJ217, and by BUILD, the project 
 which is sponsoring cooperation on EOL-^ between the University of 
 Illinois and the University of Colorado. 
 
 I would like to express my sincere appreciation to my wife, 
 Basia, for her encouragement during this study. 
 
IV 
 
 TABLE OF CONTENTS 
 
 Page 
 
 ACKNOWLEDGMENT Hi 
 
 1. INTRODUCTION 1 
 
 2. NUCLEOL FORMAL SYSTEM 3 
 
 2.1. NUCLEOL BASIC FUNCTIONS AND PREDICATES 5 
 
 2.2. POSTULATES 7 
 
 2.3. NUCLEOL IN PL/l 11 
 
 3. NUCLEOL PROGRAMMING LANGUAGE AS A MODEL FOR NUCLEOL ... 28 
 
 3-1. NUCLEOL PROGRAMMING LANGUAGE SYNTAX 29 
 
 3-2. MAPPING OF NUCLEOL INTO NUCLEOL PROGRAMMING 
 
 LANGUAGE . 31 
 
 k. THE NUCLEOL MACRO PROCESSOR NUCMAC 3k 
 
 k.l. MACRO SYNTAX $k 
 
 1+.2. NUCMAC 35 
 
 5. CONCLUSION hi 
 
 REFERENCES . k2 
 
1. INTRODUCTION 
 
 This thesis is presented as a contribution to the state of 
 the art in formal definition of programming languages. 
 
 The ALGOL 60 report (l) started the trend by showing the 
 feasibility of a formal definition of the syntax of programming 
 languages. Since then efforts have mainly been concentrated on a 
 definition of semantics. Notable among the latter is McCarthy's 
 approach (2,3) which has strongly influenced the present paper. 
 However, McCarthy applies his method only to very small parts of 
 programming languages, and it is not clear what the complexity of a 
 formal definition of a full programming language would be. 
 
 A research group at the IBM laboratory in Vienna, Austria, 
 has applied techniques which are substantially the same as McCarthy's 
 to the formal definition of PL/l. Their reports, which so far amount 
 to approximately 1000 pages, are summarized in (K) . 
 
 This paper attempts to present a formal definition of NUCLEOL, 
 a small but useable list processing language. NUCLEOL was designed by 
 Freda Fischer, Marek Irwin- Zarecki, Jurg Nievergelt, and John Sidlo 
 and has been described in Sidlo' s M.S. thesis (5). A significant aspect 
 of this thesis is its insistance that a formal definition should define 
 the language both for humans and for computers. Accordingly, the 
 definition has been partially written in PL/l and it constitutes about 
 a half of the implementation of NUCLEOL. 
 
 The plan of this thesis is as follows. In the second part 
 (following this introduction) I define a formal system called NUCLEOL. 
 
I list basic predicates and functions and indicate the axioms that 
 they must satisfy. Next I define the flow of control and the meaning 
 of the NUCLEOL instructions. This definition is written in the form 
 of a PL/1 program. In the third part I present the NUCLEOL programming 
 language as a model for the NUCLEOL formal system. The section 3*1 
 contains the syntax of the NUCLEOL programming language (somewhat 
 different from (5))' The section 3-2 shows how NUCLEOL functions and 
 predicates are reflected in the NUCLEOL programming language, thus 
 showing that the NUCLEOL programming language is indeed a model, in 
 the sense of logic, for the NUCLEOL formal system. The fourth part is 
 somewhat unrelated to the main topic of this thesis. It contains a 
 macro generator, written in NUCLEOL itself, which allows NUCLEOL to 
 be extended by means of macros. It also serves as an example of a 
 NUCLEOL program. 
 
2. NUCLEOL FORMAL SYSTEM 
 
 NOCLEOL FORMAL SYSTEM IS DEFINED TO BE 
 < ALPHABET , TERMS , FORMULAS > ; 
 
 ALPHABET = < VARIABLES , BASIC FUNCTIONS » CONSTANTS t 
 
 BASIC PREDICATES , = , LOGICAL CONNECTIVES , 
 AUXILIARY SYMBOLS > ; 
 
 THE SET OF VARIABLES INCLUDES: 
 STATE, wlELL_FORMEU_STKlNG, BLOCK, CONST I TUENT t TYPt t DIRECT ION, 
 B I T ^TR ING , CHAR AC TE R S T R I NG , NUMBER , NAME , WFS_NAME , WF S , C , D , 
 
 ANC SCME OTHERS SUBSCRIPTED VARIABLES 
 
 /* NAMES CF VARIABLES DO NUT HAVE ANY FORMAL MEANING */ ; 
 
 THE SET OF BASIC FUNCTIONS IS LISTED IN 2.1. 5 
 
 TFE SET OF CONSTANTS INCLUDES: 
 IB i iC i $D , *P , *R , 
 iLEFT_PARENT , ttU GHT.PAPE NT , 
 LEFT , RIGHT ; 
 
 THE 6ET OF BASIC PREDICATES IS LISTED IM 2.1. J 
 
 IS THE EQUALITY RcLATUN SYMBUL ; 
 
 IFF SET Uf LOGICAL CONNECTIVES INCLUDES: 
 
 I /* tiK */ i 
 
 L /* AND */ , 
 => /* IF..., THEN... #/ , 
 <=> /* IF AND ONLY IF */ , 
 -, /* MOT */ ; 
 
 THE SET CF AUXILIARY SYMtiULb INCLUDES: 
 ( /* LEFT PARENTHESIS */ , 
 ) /* RIGHT PARENTHESIS */ , 
 , /* COMMA */ ; 
 
 THc SET UF TERMS IS DEFINED INDOCTIVELY AS FOLLOWS: 
 VARIABLE IS A TERM ; 
 CONSTANT IS A TERM ; 
 
 if fun is a basic function and ti,t2,...,tn are terms then 
 
 FUN! T1,T2,. .. ,TN) ISA TERM ; 
 
 THE icT UF FURMOLAS IS uEFINED INDOCTIVELY AS FOLLOWS: 
 IF Tl AND T2 ARE TERMS THEN 
 T1=T2 IS A FORMULA ; 
 
 IF P IS A BASIC PREDICATE AND T1,...,TN ARE TERMS THEN 
 P(Tl,...,TI\i) IS A FORMOLA ; 
 
IF F0KM1 AND HORM2 ARE FORMULA:* THfcN 
 
 FUR Ml | FORM? , 
 
 FORM1 C FORM? , 
 
 FUPM1 = > FORM2 » 
 
 FURM1 <=> FuR-12 
 
 ARE FORMULAS ; 
 
 IF FORM IS A FuRMULA THEN 
 
 -.FORM lb A FORMULA ; 
 
2.1. NUCLEUL BASIC FUNCTIONS AND PREDICATES 
 
 /* ALL ARGUMENTS AND YIELDED RESULTS OF THE BASIC FUNCTIONS 
 AND PREDICATES ARE FURMAL VARIABLES. NAMES UF THE FORMAL 
 VARIABLES INFORMALLY INDICATE KINDS OF EXPECTED ARGUMENTS 
 AND RESULTS. */ 
 
 dASIC PREDICATES : 
 
 CATEGORY PREDICATES : 
 IS_bTATE( STATE) ; 
 IS_vhFS( WELL_FORMrD_STRING) ; 
 IS_BLOCK(BLUCK) ; 
 I S_CON ST I TUfcNTi CONSTITUENT) ; 
 IS_TYPE( TYPF ) ; 
 IS_CIRFCTIGN( DIRLCTIJN) ; 
 
 I S_BITS< BIT STRING) ; 
 
 I s_lhrs( chmkacterstrini;) ; 
 
 1S_.\UMB( NUMBER) ; 
 IS_NAME(NAMfc) ; 
 
 CTHER PREDICATES : 
 Ib_CuiMVERTI bLEiCONVERSl ON_MODE ,CuNSTITUENT) ; 
 CAN_PASb<SCANNER_ATTR IttOTb , PA RENTHE S I S_ATTR I BJTE) ; 
 TtSTSt TE STRODE ,CONSTI T UENT1 ,CGi\iST I TUENT2 ) ; 
 
 BASIC FUNCTIONS : 
 
 STATE LEVEL F UNC I IONS : 
 EXfcC( STATE )=WFS_NAi v ;c ; 
 CONTENT! wF S_NAi*it , STATE ) =WFS ; 
 CONTbNT_OF_EXEC( STATt )=WFS ; 
 WFS_NAMED{ *FS_NAMb) =WFS ; 
 KILL( WFS_NAME t STATF ) =Nb W_S T A T E ; 
 CREATE! wFS.NAME ,WF S , STATE) =NE ESTATE ; 
 ALTER! wFS_NAMEtWFS,STATE)=NEW - STATE ; 
 MOVES (UI RECTI ON l,WFS_NA>'.bl ,DI RE C T I 0N2 , wF S_NIAME2 , ST mT t ) 
 
 =Nt^_STATt ; 
 
 ^FS LEVEL FUNC TIONS : 
 BL0CK_4T(CIRECTI0N,WFS)=BLGCK ; 
 C0NSTITUcNT_Ar(DIRL"CTI0^wFS)=C0N5TI TOENT ; 
 DELETE (DIRECTION, WFS )=NtW_WFS ; 
 INSERT* DIRECT ION, B LUCK, WfS) =NEW_*FS ; 
 CHANGE<UIRfcCTION,CUNSTl TOENT, wFS) =NEW_WFS ; 
 SKI P_JLUCK( 01 RECTI ON , WF S I =NEtf_HFS ; 
 INBLO(iJlRECTIUN,WFS) = NfcW_WFS ; 
 SHIFT (DIRECT I ON , WF S ) = tME w_WF S J 
 RESTU*t( «FS )=NEw WFS ; 
 
 bCANNEk_ATTK_ JF( wF S ) =SC A NNE R_ATTR I BUT t ; 
 SFT_SCANNER_ATTRl SC AN.>lER_A T TR I BUTE , WFS ) =NE W_WF S 
 
CONSTITUENT LEVEL FUNCTUS : 
 TYPE_OI-(CCNSTI TUtNT)=TYPE i 
 ATT«_CF( CONSTITUENT) =ATTRI5UTE ; 
 li I TS_ INI CONST I TUENT) =3 I TST R I NG ; 
 CHRS_1N(C0NSTITUEN1 I =CHAKAC TE RSTK I NG ; 
 gUM6_IN( CCimSTI i"UENT)=NUMBtR ; 
 NAME. INI CCN ST I Tut N T ) = WF S_NAME ; 
 
 CUNVERT.DA TA(CUNVERSI 0N_M0DE ,CJNSTI TUEN1 ) =NEW_CGNST ITUENT 
 SET.ATTRI ATTP. I PUT! : t CoNSTI TUENT I =NE W_CONST 1 TUbNT ; 
 
 Af)DS( C o iM S T I TUENT1,C')NSTITUENT2) =N£w_CUNSTI 1"UENT ; 
 SUdSICCNSTITCcNTl tCONSTI TUfcNT2) = NE W_CONST 1 TUENT ; 
 MLTStCCNSTI TUENT 1 »CONSTi TUbNT 2 ) =NEW_CUNSTI TUENT ; 
 JlVS(CCMSTITUtNTl ,C:)NSTI TUE.MT2 ) =NE W_CUNST I TUENT ; 
 ANUS(CCNSTI TUENT1 , CONST I TUENT 2) =Nc *_d)NST I TUbNT ; 
 GRS<CUNSTlTUENTl f CuNSTITUENT2) = Nt W_CUNST I TUENT ; 
 JUT S( CONSTI TUENI ) =Ntrf_CuNST [TUENT ; 
 
 CONCS_LHTS( (.UN STI TUENT I, CONSTI T JE NT? ) =NLW_C JNST I T U tNT 
 COi\CS_CHRb(CiUSTI TUENT1 ,CONSTI TUENT2 ) =NEw_CONSTITUfcNT 
 S^L I T_dI TS 1 (CONSTI TUcNT) =NEw_CJNSTI TUENT 
 SPLIT_tUTS2(C JNST I TUbNT) =NE W.CONST I TUENT 
 .^PL I r_CHRSl ( CuNSTl TUENT) =NEW_CUNST ITUEkT 
 SPLIT CHRS2I CONST! TUENT) =NEW CONSTITUENT 
 
 SUUCONSTITUl.mT L^VEL ruNCTIUNS 
 JPPCSITE(CIRbCTIUN|=N£/< u I RECTI UN 
 
2.2. 
 
 PUSTULATES 
 
 FORMAL RULES AND CUNVENTIUNS : 
 • = • IS A WEAK EQUALITY RELATION, I.E. 
 
 A=B IFF EITHER BOTH A AND B ARE DEFINED AND THE SAME, 
 
 OR BOTH A AND B ARE UNDEFINED ; 
 A=B 6 IS_SCMETHING( A) => I S.SOME THI NG < B ) , 
 
 WHERE IS_SOMt THING IS ANY CATEGORY PREDICATE ; 
 
 IS. 
 
 POSTULATES 
 TYPE( TYPE) 
 
 <=> TYPE=iB 
 TYPE=*C 
 TYPE=*D 
 TYPE=$P 
 TYPE=$R 
 
 TYPE=iLCFT_PARENT 
 TYPE=*RiGHT PARENT 
 
 IS_DIRFCTICN(D) <=> D=LEFT | U=RIGHT ; 
 
 JPPOSITE(LEFT)=RIGHT ; 
 
 JPPOSITEIR IGHT)=LLFT ; 
 
 IS_DI!<ECTIOM JPPUSITE(D) ) < = > I S_D I RECT I jN ( D ) 
 
 IS_TYPE( TYPt_UF(C ) ) < = > IS_C'JN.>TlTUtNT(U ; 
 
 is.bi ts( 31ts_in(c) ) < = > 
 
 is_chrs(chrs_in(c) ) <=> 
 
 is_num3(numr_uf(c) ) <=> 
 
 is_name(.mame_in(C) > <=> 
 
 1 S_CUNSTI TUENT (CI 
 IS_CJNSTI TUENT (C) 
 IS_CUNSTITUENT(C) 
 IS_CUNSTITUENT (C) 
 
 I S_CONSTITUENT< ADDSiCl ,C2) ) <=> TYPE_UF(C1 
 
 u TYPE_OF(C2 
 
 => TYPE_OF(AU 
 
 IS.CGNSTI IlENTt SU3S(Cl ,C2) ) < = > TYPE_OF(Cl 
 
 L TYPE_OF(C2 
 
 => TYPt_UF(SU 
 
 I S_CONSTI TUENT(MLTS(C1,C2) ) <=> TYPE_OF(Cl 
 
 & TYPE_OF(C2 
 
 => TYPE_OF(ML 
 
 IS.CONSTI TUENU UIVS(C1 ,C2) ) < = > TYPE_OF(Cl 
 
 £ TYPE_JF(C2 
 
 &-.,NJJ.M3ER_Ii\i( 
 
 => TYPE_OF(Dl 
 
 lS_CQNSTITlENUANDS(GltC2) ) <=> TYPE_UF(C1 
 
 & TYPt_UF(C2 
 
 => TYPE_UF(AN 
 
 lS_CQNSTITuENT( ORS(Cl,C2)) <=> TYPt_OF(Cl 
 
 f. TYPE_UF(C2 
 
 => TYPL_ur( U 
 
 IS_CONSTITUENT(NOTS(Cn J < = > TYPE_UF(C1 
 
 => TYPE_UF(NU 
 IS_CONSTITLENT(CuNCS_bITS(Cl ,C2) ) <=> TYPE 
 
 > = $0 
 
 )=$D 
 
 DS (CI ,C2) )=*D 
 
 )=$J 
 
 )=$D 
 
 BS (C1,C2) )=$D 
 
 ) = $D 
 
 )=5>D 
 
 TS (C1,C2I )^$D 
 
 )=$D 
 
 »=$D 
 
 C2)=C 
 
 VS (C1,C2) )=$D 
 
 )=$B 
 
 )=$B 
 
 DS(C1,C2) )=$B 
 
 ) = $B 
 
 )=$B 
 
 RS (C1,C2) )=$3 
 
 )=$B 
 
 rs(cin=$B ; 
 
 (Cl)=$b 
 
& TYPE(C2)=$B. 
 
 => type.gf (loncs_bits(li,C2) )=$b 
 
 IS.CUNSTITUENriCONCS.CHRStCl ,C2) ) <=> TYPt(Cl)=$C 
 
 £ TYPE(C2) = $C 
 
 = > TYPE.GF (CUi\lCS_CHRS(Cl,C2) ) = $C 
 IS.CuNSTITLENH SPLIT_BITSliC) ) < = > TYPE_OF ( C > = $ H 
 
 = > TYPE_UKSPLlT_BITSl(C)l=*B 
 I S_CCNSJITUENT( SPLI T.bl TS2IC) ) <=> TYPE_OF ( C ) =i d 
 
 = > TYPE.GF { SPLIT__BITS2(C) )=$B 
 I S.CONSTI TUENT( SPLIT_CHRS1(C) ) <^> T YPE_OF ( C ) =$C 
 
 = > TYPE.OF ( SPLIT_CHRS1 (C) ) = J»C 
 I S_CU mSTI TUENTt SPLI T_CHRS2(C) ) < = > TYPE_Ut- ( C ) = $C 
 
 = > TYPE.OF ( SPLIT_CHRS2(C) }=$C 
 
 I S_tL <JVE« T (BLc(CONVEP >I ON.rtGOE ,CGNbTI TOENT ) 
 
 = > I S_CCNbTITUc*T(CGNVERT_UATA(CaNVERS [ON.MUDE, 
 
 CONSTITUENT ) ) 
 
 IS.CGNSTI TLCNTICGNSTl TOENT) ■> I S.tJLGCM CUNST I ruCNT ) 
 
 I TYPE.OF (CONST I TUENT)=$LEFT_PAREi*T 
 I TYPfc.GP( CONST I TUENT) BRIGHT _ PARENT ; 
 
 IS. CON SI ITLL\IT(CONSTI TGENT_aT(DI RECTI UN, WFS)) 
 
 < = > 1 S_DIRECTIGN(DIRFC F1JM) i IS.WFS(WFS) ; 
 lS_riL JlK(BLGCK.AT (DIRECT ION , WFS) ) 
 
 < = > IS.WFS(WFS) L UIkEL n UiJ = LEFT 
 
 i»-i TYPE.GF (CUM SI I TOENT.AT( DIRECT I uN , *F S ) ) = i>L L f T_P ARE^T 
 
 I I S.kFol *FS) L DlkECTIGN=RIGriT 
 
 t-.TYPE.OF (CONST I 1"0CNT_AT I DIRECTION, WFS I ) = 
 
 *.<IGHT PARENT ; 
 
 I b_ V\ F b ( 
 
 I b_ a f S ( 
 < = > 
 
 lb_*FS( 
 = > 
 
 IS_wF5( 
 
 = > 
 I S_JL^l 
 = > 
 
 lS_*Fb( 
 
 ^ = > 
 
 L 
 
 I 
 
 I 
 
 (S.BLGC 
 
 JELEFct JlkECTIONt rtFS ) ) 
 
 IS. BLOCK ( BLOCK.AT( DIRECTION ,WFS ) I ; 
 INSERT ( DIRECTION! BLOCK , *FS) ) 
 
 I S_DIkfcCTlON(DlRECTIGN) S I S.dLOCMBLGCKJ 
 
 C IS.WFS(wFS) ; 
 (NicRT (DIRECTION* BLOCK, WFS) ) 
 
 BLGCK.ATI DIRECTION, INSERT (DIRECTION, BLGCn, rfFSI ) 
 
 = "JLJCK 
 INSERT ( DIRECTION, BLOCK , WFS J ) 
 
 DELcTEl DIRECTION, INSERT (DIRECT ION, BLOCK, WFS ) ) = ^FS 
 MBLOCK.AT ( D 1RECT ION , WFS ) ) 
 
 I\SERT( DIRECTII)N,BLuCK_AT(DIRFCT I0N,WFS ) , 
 
 DELETE(DlKcCTlUN,WFS))=hFS ; 
 CHANCE (D IK EC HON, CONST I TOENT ,WFS) ) 
 
 I S_BLJC*(CO.\lSTI TOE iT) 
 
 IS.BLJCMCGNSTI TUEuT_aT (DIRECT IliN.aFS ) i 
 
 I S_CG.\STI TUE,>iT (CUNSTI TUEnTI 
 
 I YPE.GF (CONSTI TUtNT) =TYPF_OF I CONST I TUENT.AT 
 
 (DIRECT I JN,hFS ) ) : 
 KiCKSTl ruENT) 
 
 IS BLJCK(CGNSTI TOENT AT ( ul REC7 I U,\ , wF S ) ) 
 
SKIP 
 
 = > CHaNGE(OIRECTION,CONSTITOENT,WFS) = INSERT ( DI RElT ION , 
 C UNSTITUENT, DELETE (DIRECT I ON, WFS ) ) ; 
 
 BLOCK ( U, WFS) = 
 
 INSERT (UPPOSITE(D) , BLOCK_AT ( D , wF S ) ,DELETE(D,WFS)) ; 
 
 IS_KFS( INBLO( D,WFS) ) < = > IS_01RECTIGN(D) £ IS_WFS(WFS) ; 
 lS_BLOCK(BLOCK_AT(D,wFS> 
 
 = > IN6LG(D,WFS)=INBLG( D, SKI P_BLOCK ( D , WFS ) ) ; 
 TYPE_CF(CCNSTlTUENT_AT(D,wFS> )=$LEFT_PARENT G D=LEFT 
 
 I TYPE_GF(CGNSTITUENT_AT(D f WFS) ) =$RIGHT_PARENT & D=RIGHT 
 => IN6Lo7d,i*FS)=WFS ; 
 
 IS_WFS(SHIFT( DIRECTION, WFS) ) < = > I S_DI RFC T I JNC DIRECT I DM ) 
 
 L 1S_WFS(*FS) ; 
 IS_BLUCK(CCNST1 TUENT_AT( D, WFS) ) 
 
 => SHIFT(Q,WFS)=SKIP_BLGCMD f WFS) ; 
 1 S_kFS( SHlFT(D,rtFS) ) 
 
 = > SHIFT( LiPPOSI TE (0) , SHIFT(DtWFS) )=wFS ; 
 CONSTITOENT_AT(OPPOSI TE ( D) , SH1F Ti 1 , WFS ) ) - 
 
 CO.NSTITU£NT_AT(D,WFS) ; 
 IS_fcFS( INBLGID1 ,WFS) ) 
 
 & INBL0(Dl,WFS)=IN3LJ(01,SHlFT<D,ViFS) ) 
 = > IS_bL JCMCGNbTI TUE,\jT_AT(D,WFS) ) ; 
 SHI F 1 { D, 1 1MB LOO ,WFS) ) = SK I P_bLUCK( D , Sh I FT(UPPUiI7b(D), 
 
 INBLJ(OPPGSITE( J) ,wFS)) ) ; 
 
 IS_*FS(RESTGRE< WFS) ) < = > IS_WFS(WFS) ; 
 RESTORE! RESTORE! WFS) ) =RE STORE ( WFS) ; 
 IS_CIRECTICN( D) L IS_wFS(WFS) 
 
 => RESTORE(WFS)=RESTCRE! SHlFT(D,WFSM ; 
 
 IS_WFS(CGNTENT(NAME, STATE) ) => I S_NAME ( NAME ) 
 
 U I S_STATE(STATE) ; 
 IS_STATb( STATE) => I S_WF S( CONTENT (EXEC ( ST ATE ), STAT E ) ) ; 
 CGNTENT_GF_EXEC! STAT E ) sCOw TENT ( EXEC I ST ATF ) , ST ATE ) ; 
 
 WF S_NAMED( NAME) =CONTENT< NAME , STATE ) 
 
 WHcRE STATE IS THE CURRENT SfATt; 
 
 IS_STATE(KILL(NAME, STATE ) ) <= > I S_WFS ( CONTENT ( NAME, ST ATE) ) ; 
 I S_S T ATE ( CREATE (NAME, WFS, ST ATE ) ) 
 
 < = > I S_ NAME (NAME) L IS_WFS(WF:>) £ I S_ST ATE ( ST AT E ) 
 £-.1 S_V»FS( CON TENT (NAME, STATE) ) ; 
 I S.STATE (CREATE (NAME, WFS,S TATE) ) 
 
 = > CCNTE JT(.\AME,CREATE(NAME, WFS, STATE) )=WFS ; 
 IS_STATE(CREATE(NAME,rfFS,STATE)) 
 
 = > KILL(NAME, CRE ATE ( NAMc , *F S , STATE) ) =STATE ; 
 I S_ WFS! CONTENT! NAME, STATE) ) 
 
 => CRE ATE (NAME, CONTENT ( NAME, STATE ) , K1LL( NAME, STATE) > 
 
 =STATE ; 
 
 ALTER ( \l AM F , WFS, STATE )=CRFATE( NAME , WFS, KILL (NAME, ST ATE) ) 
 
1i)V£S(CL iNAMElfD2tNftME2 t bTATb) 
 
 = ALTEk( NAME It DELETE! J 1 ,C()NTENT( NAME1 , ST ATE ) ) t 
 
 10 
 
 ALTbR( NAME2 t INSERT! U2 , 
 
 BLUCK_AT(D1 ,CUN TENT (NAME It ST ATE ) ) ( 
 CONTENT ( NAM E2 t STATE ) ) , 
 STATE)) ; 
 
11 
 
 2.3. 
 
 NUCLEUL IN PL/1 
 
 MUCLEUL: 
 DECLARE! 
 
 DECLARE 
 
 OFLLAKE 
 
 DECLARE 
 
 LEFT 
 RIGHT 
 NEUTR 
 ^>TATE 
 NEw_S 
 ARG ( 
 ARG1 
 ARG? 
 ARG 3 
 DECLARE!ACTUA 
 BINAR 
 
 DECLARE 
 
 DECLARE! 
 
 DECLARE 
 
 PROCEDURE OPTIGiMStMAIN 
 MOVE»CUPYf RSTKtSHFTtCV 
 ADDf SU3 tMLTfOIVt AND tUR 
 CCiNIC, SPLT,TEST) 
 ENTRY(3INARY FIXED) RE 
 $6 CHARAC 
 
 $C CHARAC 
 
 $D CHARAC 
 
 $P CHARAC 
 
 $R CHARAC 
 
 iS CHARAC 
 
 $LEFT_PARENT CHARAC 
 $KlGHT_PARENT CHARAC 
 XNUNACTIVfc CHARACTER! 1 
 NUNACT1VE CHARACTER11 
 SUCCESS CHARACTER! I 
 FAILURE CHARACTER! 1 
 UNDEFIN CHARACTER! 
 DATA CHARACTEKll 
 rt CHARACTER! 1 
 
 CHARACTER! I 
 CHARACTER! 1 
 AL CHARACTERil 
 rtlNARY FIKED INI 
 TATE, STATED BINA 
 3) BIMARY FIXED, 
 BINARY FIXED DEFINED ARb 
 BINARY FIXED DEFINED ARG 
 UNARY FIXED DEFINED ARG 
 L_ARGl,ACTUAL_Ai<o2 ,ACTUA 
 Y FIXED; 
 
 ) ; 
 
 RT, 
 »NGT, 
 
 TURNS (0 
 TER! 1) 
 TER(l) 
 TER(l) 
 TERI1) 
 TERU) 
 TER(l) 
 TER(l) 
 TEIU1 ) 
 ) I N I T I 
 I N I T I 
 I \IITI 
 I NIT I 
 INIT 
 I NI T I 
 I M I T I 
 INI1I 
 INITI 
 INITI 
 TIAL!°) 
 RY FIXE 
 
 INARY FIXED) 
 
 ) 
 ) 
 ) 
 
 1) 
 
 ) 
 ) 
 
 ) 
 ) 
 ) 
 
 INITIAL! 
 
 INITIAL! 
 
 INITIAL! 
 
 INITIAL! 
 
 INIT I AL( 
 
 INITIAL! 
 
 INITIAL! 
 
 INITI AL! 
 
 AL( 'X' 
 
 AL( , 
 
 AL! 
 
 AL( 
 
 IAL! 
 
 AL! 
 
 AL( 
 
 AL! 
 
 AL! 
 
 AL( 
 
 iV 
 
 S' 
 
 F' 
 
 •J 1 
 
 i)< 
 
 L' 
 <• 
 N« 
 
 D; 
 
 (1), 
 
 (2) , 
 
 (3) ; 
 
 L_ARG3) 
 
 B» 
 C» 
 D» 
 P» 
 R« 
 S' 
 !• 
 )• 
 
 DECLARE UNDEFINED BINARY FIXE J INITI AL(-l) 
 DECLARE IS_STATE 
 
 fcNTRY!BINARY FIXED) 
 RETURN S!B IT! 1) ) , 
 
 1 S_*F S 
 ENTRY!bIN4RY FIXED) 
 RETURNS!bIT( 1 ) ) , 
 
 I S.dL.oCK 
 ENTRY lb INARY FIXED) 
 RETUPNS!BIT!1> ) , 
 
 I S_C0NSTI TUENT 
 ENTRYIBINARY FIXED) 
 RETURNS(BIT( 1) ) , 
 
 IS.TYPE 
 E N TRY! CHARAC TcR! 1 ) ) 
 Re TURNS!bIT( 1 ) ) , 
 
 IS_D1RECTIU\ 
 
IZ 
 
 e:m ikyjcharactfpi i ) ) 
 returns! b1t( 1) ) , 
 
 I b_CUNVERTIBLE 
 EnTRY( BINARY FIXE0»3lNARY FIXED) 
 KETURNS<BITI 1)1 J 
 i)ECLARl: f.AN_PASS ENTRY(B1T(8),LUT(8)) 
 
 RETURNS(BIT( 1) ) 
 
 JECLAPt" NlCSTEP 
 
 ENTRY (BINARY FIXED) 
 RtTUKNSltUNARY FIXED) ; 
 
 JECLAHE EVAL 
 
 ENTRY (BINARY FIXED) 
 RETURNSIrtlNARY FIXED); 
 
 JtCLA<E EXEC 
 
 ENTRY (tilNARY FIXED) 
 KEru«?Nb(CHA»<ACTER( 8) ) , 
 
 CCNTEimT 
 ENTRY ( CHARACTER! 8) , BINARY FIXED) 
 RETURNSIBINARY FIXED) , 
 
 wF S_NAMEO 
 _NTR VI CHARACTER!* ) ) 
 Rt TU Q NS(B I NARY FI XtD) , 
 
 CCNlt NT_GF_EXEC 
 ENTRYtBlNARY FIXED) 
 RETURNS (BINARY FIXED) ; 
 DECLARE KILL 
 
 "ti\TRY( CHARACTER! 3) t BINARY FIXED) 
 RETURNS! BINARY FIXEJ), 
 
 LREATE 
 ENTRY!CHARACTER(8) , BINARY FIXED, BINARY FIXEU) 
 Re TURNS (BINARY FIXED) , 
 
 ALTER 
 tNTRY(CHARACTER(8) , BINARY FIXED, BINARY FIXED) 
 RETURNS(BINARY FIXED), 
 
 MCVFS 
 t xl TRY {CHARACTER ( i ) , CHA* AC TF R ( 8 ) , 
 
 CHARACTER ( 1 ) , CHAR AC TfcR ( 8 ) , BINARY FIXED) 
 RETURNS! BINARY FI XEJ ) 5 
 DECLARE D A^ SE_ANU_SK1P 
 
 E.MTKYlBlNARY F I X r D , 8 I \A kY FIXED) 
 RE f URNS (B I .MAR* r IXEO) ; 
 DECLARE bXFCJTE_I NSTPUCTIUN 
 E *T«Y (BINARY F IXED) 
 RE TURNS (81 NARY FlXcJ); 
 JECLiRE aLlCK.AT 
 
 b N IRY ( CHARACTER ( 1 ) , BINARY FlXEJ) 
 RETURNS (BINARY F I XEJ I, 
 
 CCNSTI TLENT_AT 
 EN TRY! CHARACTER (i I »8INA*Y FIXED) 
 RE TURNS (BINAR Y FIXED), 
 
 D E L t TE 
 
13 
 
 ENTRY(CHARACTER( 1 ) .BINARY FIXED) 
 RETURNS(BINARY FIXED) , 
 
 INSERT 
 ENTRY(CHARACTER< 1 ) ,BINARY F I XtD , BI NARY FIXED) 
 RETURNSIBINARY FIXED), 
 
 CHANGc 
 ENTRY(CHARACTER( 1) .BINARY FIXED, BINARY FlXtD) 
 RETURNSIBINARY FIKEDI, 
 
 ( SFIFT, INBLU) 
 E NTRY( CHARACTER ( 1 ) .BINARY FIXED) 
 RFTURNS(BINARY FIXED), 
 
 RESTORE 
 ENTRY(B1NARY FIXED) 
 RF.TURNSiBl.MARY FIXED) ; 
 DECLARE SCANNER_ATTR_UF 
 ENTRY (BINARY FIXED) 
 RETURNSiCHARACTER ( L) ) , 
 
 SET_SCANNER_ATTR 
 FNTRY(CHARACTER( 1 > .BINARY FIXED) 
 RE TURNS* BINA'RY FIXED); 
 DECLARE TYPE.GF 
 
 EN TRY (BINARY FIXED) 
 RETURNS (CHARACTER! 1 ) ) , 
 
 ATTR_OF 
 ENTRY(BINAKY FIXED) 
 RbTURNSiCHARACTEK ( 1 ) ) , 
 
 B1TS_IN 
 ENTRY(BINARY FIXED) 
 RFTURNS(BINARY FIXED), 
 
 CHRS_I,N 
 E.\i TRY (BINARY FIXED) 
 RETURNS(BIi\jAR Y FIXED), 
 
 NUMB..IN 
 CNTRY(BINARY FIXED) 
 RETURNSIBINARY FIXED(3i)li 
 
 NAME_IN 
 E,MTRY(dI NARY FIXED) 
 RE TURNS ( CHAR AC TER( 8) ) ; 
 DECLARE SET.ATTR 
 
 ENTRY i CHARACTER ( 1 ) .BINARY FIXED) 
 RETURNSIBINARY F I XtD) ; 
 DECLARE CCNVERT_DATA 
 
 LNTRYIBIMARY FIXED, BINARY FIXED) 
 RETURNS (BINARY FIXED) ; 
 DECLARE ( ACDS, SUbS.MLTS.DI VS) 
 
 ENTRYIBINARY FIXED, BINARY FIXED) 
 RETURNSIBINARY FIXED) ; 
 DECLA«E( ANUS, DRS) 
 
 EmTRY(BINARY FIXtD, BINARY FIXED) 
 KETURNS(BINARY F IXEJ) , 
 
 NUT S 
 b MTRY ( BINARY F IXED ) 
 
 keturns(binary \-ixto ) ; 
 
14 
 
 UbCLAKb(CG\CS_i>ITS,CUNCS_CHRS) 
 
 F.N I RY lb I NARY FIXED* 31 NARY FIXED) 
 
 RET UK ^S( Li I NARY FIXED); 
 JtCLAKtK SPL IT_BlTSl,SPLlT_ciITS2,SPLIT_CHRSl , SPL IT_CHR^2 ) 
 
 F.AITKY (IsINARY FIXED) . 
 
 RETURNS (BINARY FIXED) ; 
 DECLARE TFbTS 
 
 E-N1RYI BINARY F I XcO ,6 I NARY FIXED.BINARf FIXED) 
 
 RE TURN 5(13 I T( 1 ) ) ; 
 OtCLARE NEw_CUNSTITUENT BINARY hlXED; 
 ULLLARt ERR_MS(i 
 
 ENTRY(CHAKACTER( b<~ ) ) ; 
 
 Du WHILE ( IS_STATE( STATE)) ; 
 
 3TATE=NUCSTEP( STuTt: ) ; 
 END ; 
 
 -it TURN; 
 
 -xuCSTtP :PRCCEDURt( ST a TE ) a I imAt.y FIXED; 
 
 DECLARE STATE BINARY FIXED; 
 
 DtLLA ?b NLS LilNARY FI XED ; 
 
 NLS=C(JNST ITJENT_AT(RIoHT,CuNTE\T_GF_EXrC(STATE) ) ; 
 IT TYPb_UF(NJS) =iC L 
 
 ATTk_uF (NUS) = , K« 
 THEN lu; NE *_STATE=EXtCUTc_lNSTRUCTI JN1ST ATE ) ; 
 RE TURNl NEw_STATb ) ; 
 
 end; 
 
 if rYPh_UF(NUS) =*LEFT_PARENT 
 T E-LiNi Do; 
 IF 
 CA\_PASS( SCANNER__ATTK_JF ( CGNT ENT _."JF_E X tC ( STATt ) ) , 
 
 ATTR_uE(NUS ) ) 
 ThE\ NE W_S 1 ATE =ALTER(EXfc CIST ATE) , 
 
 SLT_SC ANNE R_ ATT RiNONACT IV £i ShIFT 
 (RliiHT tCJ\TtNT_GF_tXEC(STAT c) ) ) , 
 iTATE) ; 
 EL SL Ntfc_STATc=KLiVES ( R I G H T , Ex EC( STATE ) , 
 
 LEFT ,tXEC(STATE) , 
 STATE); 
 
 Rb rURN(NfcW_STATE) ; 
 END; 
 IF TYPE_UF( <*uS)=$RlGHf_PARENT 
 
15 
 
 THEN 00; 
 IF 
 CAN_PASS( SCANNER_ATTR_0F<C0NTENT_JF_EXEC(STATE) ) t 
 
 ATTR_UFINUS) > 
 THEN MEw=STATE=ALTER(EXEC<STATE) , 
 
 SET_SCANNER_ATTRd\ JN ACT IV E, SHI FT 
 ( R10H T, CON TENT_GF_EXc CIST ATE) ) ) t 
 STATE) ; 
 ELSE Nt W_S T A TE = ALTER (EXE CIST ATE) , 
 
 INULU(LEFT,CU,\iTcNT_OF_tXEC( 
 
 STATE) ) , 
 STATE) ; 
 RETURN(NEW_STATE) ; 
 END ; 
 IF TYPE_GF(NUSJ=$R & 
 
 AT TR_0F< NUS) =NEUTRAL 
 ThtiM DO; 
 
 N E fc_S TATE =ALTER(NAME_IN( NUS) t 
 
 St T_SCAiMNER_ATTR (NUNACT IVE , CONTENT ( 
 NAHE_lMlNUS) , :>TATE) ) t 
 
 ALT.ERtEXEC(STATE) , 
 St: T_SCANNER_ATTP (DATA, 
 C UN TE N T_uF _E XEC (ALT ERIE XEC( ST AT L ) , 
 
 SHIFT (RIGHT , 
 CONTENT_aF_tXEC( STATE) ) , 
 
 STATE) ) ) , 
 STATE)); 
 RETURN(NE«_STATF) ; 
 END ; 
 /^MARKER CASE*/ 
 MEfc_STATE=ALTER(EXEC( STATE) , 
 
 bHIFT( RIGHT ,CU\iTENT_OF_tXFC(STATc ) ) , 
 STATE) ; 
 RETURN! Ntw.STATE ) ; 
 
 ENC NCCSTEP; 
 
 EXECOTE 
 DECLARE 
 
 INS IRUCTION: 
 STATE BINARY 
 
 PRUCFDURE( STATE) BINARY FlXtb; 
 FIXED ; 
 
 DECLARE KEY CHAR AC TER ( 4 ) ; 
 K t Y = CHP S_ I. si ( C ON ST I TOE:MT_A T(R I GHT, CUNT EnT_OF_lXl CIST ATE) 
 
 IF 
 IF 
 IF 
 IF 
 IF 
 IF 
 IF 
 IF 
 IF 
 
 KEY = 
 KEY = 
 KEY = 
 KEY = 
 KFY = 
 <EY = 
 KEY = 
 <EY = 
 KEY = 
 
 JVOVE 
 COPY 
 SHFT 
 
 RSTR 
 
 TEST 
 
 ADD 
 
 SUB 
 
 NLT 
 
 CIV 
 
 THEN RE TURN (HOVE! P ARSE_AND_SK I P ( c 
 
 THEN KE TURN (COPY! PARSE_AND_SK I P I 
 
 THEN RE TURN! SHFT( PARSE.ANO. 
 
 THEN RE TUKNI RSTRl PARSE_AND. 
 
 THEN RETURN(TtST( PARSE_Ai\.U_SK I P ( 3 , ST AT E ) ) 
 
 THEN RtTURiMUDD ( PARSE_AI\D_SK I P ( 3 , ST AT E ) ) 
 
 THEN RETURN! SUB( PARSE_AND_SK I P { 3 , ST AT E ) ) 
 
 THEN RE TORN! MLT ( PARSE_AND_SK I P ( 3 , 
 
 THEN RETURN! DIV( PARSE AND SKlP(3 t 
 
 STATE) ) 
 bTATt) ) 
 .SKIP! ItSTATE) ) 
 SMPI 1, STATE) ) 
 
 STATE) ) 
 STaTE) ) 
 
16 
 
 IF 
 
 KEY= 
 
 • AND ' 
 
 THEN 
 
 IF 
 
 KbY = 
 
 •uR • 
 
 THEM 
 
 IF 
 
 KFY = 
 
 •NOT • 
 
 1 HEN 
 
 IF 
 
 KEY = 
 
 •CUNC • 
 
 THEN 
 
 11- 
 
 KEY = 
 
 • SPLT' 
 
 THEN 
 
 IF 
 
 i<ry = 
 
 •C VRT« 
 
 THEN 
 
 REFURN( AND(PARSE_AND_SKIP.('3,STATE) ) 
 RETURN! UR(PARSE_AND_SKIP(3,STATE)) 
 RETURN! NOT(PARSE_AND_SKlP( ESTATE) ) 
 RETUKN(CUNC(PARSE_AND_SKIP(3, STATE) ) 
 RE TURN ( SPLT ( PARSE_AND_SK I P ( 2 , S T AT E ) ) 
 RETUR.'HC VRTI PARSE_AND_SK I P ( 1, STATE) ) 
 
 CALL ERR_MSG('KEY rtOftO 1 j NCT PRGPERM 
 RETLRN(LNDEFINtD) ; 
 END F XECUTE_.INSTRUCTI.JN; 
 
 PA^SL_ANJ_SKIP :PKOCtJU<c(f\iiJ iJcK »i>TATE ) BlNA<Y F I X E u \ 
 DECLARE NUiMbtR BINARY FIXED, 
 STATE BINARY FIXEUJ 
 CECL.aRE STATE1 BINARY FIXcJ; 
 SrATEl=ALTE*(EXEC( STATE) , 
 
 SHIFT (RIGHT ,CJNTENf_UF_FXcC( STAT E) ) , 
 STATE I ; 
 uo \=1 TC NUMBER; 
 
 AkG( N)=6LUCK_AT( RIGHT, CUNT ENT_UF_EXEC(STAT El ) ) ; 
 IF -WS_UEFINED(AKG(N) ) 
 ThbN DC; 
 
 CALL ERR_MSG( 'NJT ENJJGH A^oUMENTS IN AN INSTRUCTION 1 
 
 ); 
 
 RETLRN(UNDLFINEU) ; 
 END; 
 SlAT_l=MJVES(RlGHT f EXE_( STATE) » 
 LEFT,EXEC( STATE) f 
 
 STATE) ; 
 
 t\u ; 
 
 RETLRNI STATE1 ) ; 
 tND P AR Sc_ANu_SKlP; 
 
 40 Vt : PROCEDURE (STATE ) BI\AKY F I XEO; 
 DtCLARE STATE BINARY FIXEu; 
 
17 
 
 IF TYPE_UF(ARG1)-=$R 
 I TYPE_QF( ARG2) -=SR 
 THEN CALL ERR_MSG( 
 
 •TYPE OF ARG1 DP. ARG2 IN MOVE IS AID GOOD 1 ); 
 RETURN* UNDEFINED) ; 
 IF NAME_IN(ARG2) ='SYS.FSL* 
 THEN DO; 
 
 IF IS_DIRECTIUN( A T FR_UF < ARG1 ) ) 
 THEN RE TURN ( ALTER (NAME_IN< ARG1) , 
 
 DELETE ( ATTR_OFURGl) ,rfFS_NAMED 
 (NA,4E_IN( ARGl) ) ) , 
 STATED ; 
 
 RE TURN ( KILL(NA.4E_IN( ARGl) , STATt ) ) ; 
 END ; 
 IF IS_DIRECTH)N{ ATT R_OF ( ARGl) ) 
 L IS_CIRECTIJN( ATTK_CF( ARG2) ) 
 THEN RETURN! 
 
 MUv/GS( ATTR_UF( ARGl ) , NAMt_ I i^ { ARGl ) , 
 
 ATTR_UF { ARG2 ) , NAME_IN< ARG2 ) , 
 STATE) 
 
 ) ; 
 
 IF -IS.DIREC riGN< ATTR_UF (ARGl) ) 
 6 -«IS_DIREC1 IGN( ATTR_JF ( ARG2 ) ) 
 THEN RE TUkN (CREATE (NAME_IN( ARG2) , 
 
 WF S_NAMED(NAME_IN( ARGl) ) , 
 KI LL( NAMt_IN< ARGl) t^TATn) ) ) ; 
 CALL ERR_Mbu< • ARGl UR ARG2 IN MJVE lb NO GOOD') 
 3ETURN(UNDEF INFU) ; 
 END MCVE; 
 
 CORY: PRUCEGUREt STATE) BINARY FIXED; 
 DCCLARE STATE titNARY FIXED-; 
 IF TYPF_UF(A«G2) -=i»R 
 THtiN RETURN( UNDEF INED) ; 
 IF TYPE_:DF( ARGl) =$R 
 THEN DO; 
 
 IF Ib_DiRcCTUN( ATTR_JF(ARG1) ) 
 i, IS_Q1RF.CTIUN( ATI R_UF ( ARG2 ) ) 
 (HEN RE TURN I ALTER ( NAME_IN( ARG2 ) t 
 
 I NSERT( ATT R_OF ( ARG2 ) ,HLOCK_AT ( 
 AT TR_dF( ARGl) ,WFS_NAMEL( JAME_ IN ( ARG 1 ) ) ) , 
 r.' c S_NAKED(NAMc_IN( ARG2) ) ) , 
 >>TATL) ) J 
 IF -.IS.DIRECTIUNl ATTR_'JF ( APG1 ) ) 
 6 -.IS ul.<tCTIuN( AT l'R UF(ARG2)) 
 
id 
 
 then oo; 
 IF -I S_WFS(CJNTtNT(NAME_IN( ARG2) , STATF) ) 
 THEN RETJRN( 
 CREATE(NAME_lN(ARi>2) t WF S_NAMED { NAME. I N ( AR G 1 > ) , STATE) 
 
 ) ; 
 
 CALL ERR_MSG( 
 •ATTE.1PT TO CREATt SECOND rtFS WITH THh SAME NAME' 
 
 ) ; 
 
 RETURNIUNDEF I;>»ED) ; 
 END; 
 CALL EPR_MSG( <4kul OR ARG2 IN CLP/ IS NO GuOD' ) ; 
 KFTDRN( UNDEF I \IED ) ; 
 END; 
 RE TURN! ALTER (NAMfc.lNl Ar<u2) , 
 
 iNSbRT ( ATTR_OF ( ARG2 ) ,ARGI r WFS_NAMbD( 
 
 NAME_IN(ARG2) ) ) t 
 STATb) ) ; 
 M U C j P Y ; 
 
 RSTRcPRDCECUREI STATEM1NARY 
 >lCLA<(. STATE 3INARY FIXED; 
 
 IF TYPF_JF(ARG1)-«=»R 
 
 THEN Cu; 
 
 IK E D ; 
 
 CALL ERP_MSG( «ARG1 IN RSTR IS Nul A REFERENCE 1 ); 
 RETURN! U;\DLF [ NED ) ; 
 END ; 
 IF I S_U I RECTI ONI \TTM_UF j ARGl) ) 
 
 I F b N D U ; 
 
 IF mAMc_I m( ARGl ) =lXlC( STATE) 
 THFN STATEl=ALTER(cXFClSTATF| i 
 
 St r_SCANNER_ATTk(NJNACT IV Ei 
 
 C JNTE NT _LF_FXtC( STATE) ) t 
 SI ATT ) ; 
 lLSE STATEl=oTATh ; 
 RFTURNI ALTtRl NArtE_l \< ARGl ) , 
 
 I.NliLUl \1 Tk_GP( AkGI ) ,Cu\T Ei\T <NAME_IN 
 
 (ARGl ) iSTATtl ) ) t 
 STATtl ) ) ; 
 END; 
 IF NA,ML_IN(ARG1)=EXEC1STATEI 
 THEN STATEl=ALTt K(EX(- C(i>TATt ) , 
 
 SET_SCA \|.NcR_AITR UNQNACT IvEi 
 
 CUNTENT_nF_EXEC<STATtl ) , 
 STAT;:) ; 
 tLSL STA Ttl=STATE; 
 ^.ETUPNI Ai_TtR( NAME_IN( ARG 1 ) f 
 
19 
 
 kE S T OR t ( CUNTE NUN AM E_IN( AKG1) » ST AT El) ) , 
 STATED ) ; 
 
 END kstk; 
 
 SHE T:PkUCEDUPE( ST ATE I 31 \iAKY F 1XED; 
 DECLAPb STATE BINARY FI*Eu; 
 \t TYPE_CF ( ARG1 ) = *<? L 
 
 IS.DIKEC HUNl AT7k_UF( ARGl) ) S 
 NAMt_lN( ARGl )-=bXEC(STATE) 
 THEN RE TURN ( 
 
 ALTER! i\AME_IN( ARol) , 
 
 SHIFT! ATTR_OF (ARGl) ,rtF S_NAMtD( iSiArtE_IN 
 
 ( Ah oil ) I » 
 STATE) 
 
 ) ; 
 
 ELSE CALL ERR.MSG ( • ARo 1 IN SHE! IS NO GIjCD')! 
 Rfc TlRNI UNQEF 1NEDI ; 
 
 END 5hFT; 
 
 CVR T: PRO C EL LRU STATE 131 .\IAkY FIXED; 
 
 JECLARE 
 DFCLARE 
 
 STATE BINARY FIXED 
 TYPE ATTRIBUTE TAr- 
 
 ( 
 
 ' Li 
 
 •c 
 
 'J 
 
 I p 
 
 • ( 
 • ) 
 
 •R 
 
 • (N 
 
 • )'M» 
 
 •BS 
 
 ■Cn 
 •DS 
 • P8 1 
 •RL 
 •IS 
 ' IS 
 
 DECLARE ACTUAL CUMVEkSIiH 
 
 I M I T I A L ( 
 
 •BC« , 'BO 
 
 • C b • , • C 
 
 •Ob' , 'DC 
 
 •PC 1 , 
 
 •PC ) ; 
 
 £<28) CHARACTER (2) INITIAL 
 
 •PO 
 
 • P«* 
 
 • (C I 
 
 'AJOc rAHLE(K') CHARALTFR(2) 
 
 CP 
 
 CK 
 
 DECLARE CCNVERS1CJN_HUDE CHARAC TER( 3 ) t 
 
 ( TYPE.CHR ,AFTR_CHR , TY PE_URG , ATTF-'_ur G I CHAR AlT b« ( 1 ), 
 
 ( TYPE.ATTR tTYPb_TYPc) CHARAC TER I 2 ) ; 
 IF TYPE CH ( ARG2 I =tR & 
 
?0 
 
 I 5_DIREC T IUiM( ATTR_JF ( ARG2) ) 
 THE \i ALTUAL_ARG?=Cl>NSTl T UE N T_A T ( ATTR_UF'( A KG 1 ) , 
 
 WFS_NAMECMNAMe_IN(ARG2) ) ); 
 LLSh Ui ; CALL ERR_MSG( •ARGZ IN CVRT IS NO GJuJ' ) ; 
 RETURN! UiMUEF INEU) ; 
 END ; 
 
 ALTUAL_ARol=EVAL( ARG1) J 
 If I YPL.CF (ARGl)=iC 
 
 ThtN CGNVERSIGN_MUDE=ChRS_iN( AkGI ) J 
 F!LSF i)U ; 
 
 If TYPL_OF( ARG1) =fR l 
 
 1 S_U IRl-C I UJN( AT Tk_UE (mRGI) ) 
 THE;m ACTUAL_ARG1=CUNST I Ttjr->JT_AT ( ATT R_UF ( A kg I ) t 
 
 wF S_N AM l U I N A -1 c _ I M ( A ■< G 1 ) ) ) ; 
 LLh DC; C\LL ERk_iMSG( • ARtil IN CVRT lb NU GfUD 1 ); 
 RE TufN( UNDtF LNEJ > ; 
 b \l); 
 
 I I T YPh_GE( AC TUAL_ARG1 ) = *C 
 
 Tt-t. * CUNVEH SI ijN_ ■! JUl- = 1 Hi<S_l N( AC TUAL_AMG1 ) ; 
 LI Sr UGJCALL ck ! '_-1^( 
 
 'ARG1 UP ACTUAL_ARGl I J CVRT IS Nu GJOG' ) I 
 
 Kc TCR\( UNDEF iNL J) ; 
 END; 
 END ; 
 
 1 YPE_ChR = SUbi>TR (CONVERT UN_MJDE ,1,1); 
 ATI P_CHR = SlRSTR (C UN VERS I J.J_WtiUE ,3,1) ; 
 T YPE_OF G=TYPE_'JF ( AC TUAL_ARG2 J ; 
 ATTR_GRG = AT Tk_OF { ACTJAL_mKG2 ) ; 
 IE IYPE_CH» = « ' THEN TYPE_GHR = TYPE_tJkG; 
 IE .\TTR_LHk = ' • THEN A 1 TR_CHR= ATTR_ORG; 
 TYPt _ATTR=T YPb_CHR | | ATTp_CHR ; 
 T Yr't _TYP£=TYPE_URG j | TYPE.CHR ; 
 
 CHECk_CCNVE RSI'J Y_MODE : 
 
 i-u 1=1 Tl l)M( TYPE_ATTRI rtUTh_TA.iLE.l ) ; 
 
 IF TYPE_ATTR = rYPE_ATTRliiJTE - TAbLF( IJ 
 
 THEN GUT J CVRT1 j 
 r NJ CHECK_CQNVERSIOlM_«1t)Ot ; 
 CALL ERR_NSG< MLLEGAL LoiM^/c RS I G.< MUDE Ih 
 ;nETLR ^( UNCLE [NED I ; 
 
 LVRT' ) 
 
 CVPTl: 
 
 IE TYPt_CEK-.= TYPE_URG 
 
 1 EL J DO ; 
 
 E I \ G_ AC T G AL_C GN VE RS I uN_rtUDt! : 
 
 li. 1=1 Tl LjI'K ACTUAL_CuN\/EKSlL!N_MGOE_TAbLE, 1 ) ; 
 
 IF TYPt_TYPE=ACTUAL_GONV6RSl JN_MCDE_1 ABLE! I ) 
 
 THEN GO TJ CVRT2 ; 
 ENJ F INu_AC rjAL_CONVcRSl JN_MuJE ; 
 CALL cRR N'SGJ • I LlZGmL CCWERSIuN REOUtSTtO Ik CVRT'); 
 
21 
 
 RtTLKN( UNDEFINED ) ; 
 
 CVRT2: 
 
 IF IS_CCNVERTIBLE( 1 , ACTUAL_ARG2 ) 
 THEN 
 
 ACT L AL_ARG2 =C CNVLRT.DAT A ( I , ACTUAL_ARG2) ; 
 ELSE DO; CALL ERR_MSG( 
 
 'ACTUAL.ARG2 IN CONVERT IS NOT CONVERTIBLE" ); 
 RETURNf UNDEFINED I ; 
 
 END; 
 
 END; 
 
 IF ATTK_£HR-i = aTTK_URG 
 
 TFEN ACTUAL_ARG2=SFT_ATTR( A T TR_CHR , AC TU A L_ARG2 ) ; 
 
 RETCRNl 
 
 ALTER ( NAMb_lN( ARG2I » ■ 
 
 CHANGE ( AT IR_GF (ARG2 ) t ACTUAL. AR ,2 , 
 
 tfFS_NAMb0(NAtfE_If\i( ARG1) ) ) , 
 STATE) ) ; 
 END CVRT; 
 
 ALL :PRGCEDLRE( STATE )B I NARY rl XbO? 
 DECLARE STATE bINAR/ FlXtu; 
 ACTUAL. ARG1=EVAL{ ARG1) ; 
 ACTUAL_ARG2=EVAL( ARG2) ; 
 IF TYPE_UF( ACTUAL_ARG1 ) = 10 
 £ TYPE_OF( ACTUAL_ARG2 ) =*D 
 £ TYPE_UF ( ARG3 ) =±R 
 S I S_D IREC II OP, ( ATTR_GF (ARG3I ) 
 THEN UU? 
 
 NE'rt_CUNSTI rUENT = A DOS ( ACT JAL_ARG1 t ACT JAL_mRG2 ) ; 
 
 RE TURN ( ALTER ( NAMb_lN< ARui) , 
 
 INSER T( ATTR_GF ( ARu3 ) iNbW_CuNS T 1 TJE fT t 
 WFS_NAMEU( NAMt_IN< aRG3) ) ) » 
 STATt) ) ; 
 END.; 
 CALL ERR_MSG( 
 
 •"AIM ARG UR A.N ACTUAL_ARG IN ADD IS ,mu oJuJ' ); 
 RE TORN ( L'NOEF I NED) ; 
 cND ADD; 
 
 >UB :PRuClDCkC ( STATE )B IiARY Fl XEOJ 
 
21 
 
 dl'CLARE STATE dlNARY FIXED; 
 \CTuAL_AkGl=EVAL( ARG1) ; 
 ACTUAL_APG2=EVAL! ARG2 ) ; 
 IF TYPE_JF( ACTUAL.AKG1 ) =$0 
 £ T *Rt_GF ( ACTUAL_ARG2 ) =*D 
 S TYPE_GF( ARG3)=$R 
 f. I b.UlKEC FT JN( ATTRJjF (ARo3) ) 
 Thu,^ DO; 
 
 NEW_CGNS1 I TUENT=SJdS! ACTJAL_ARG1 , ACTUAL. ARG2 ) ; 
 
 K[ TURN! ALTER ( NAME _I\i( AUG*) » 
 
 INSERT! ATTR_OF( ARG3) ,NErt_CUNST lTUENTi 
 WFS_NAMk U I:\iAMb_ IN ( ARG3I ) ) » 
 STATE) ) ; 
 
 END; 
 CALL ERR_MSG! 
 
 •AN ARo CK AN ACTUAL_ARG IN SUQ IS MO &JLU* ) J 
 RETURN! UNDEF INED) ; 
 W SLo; 
 
 ML T :PRoC tD URE( STAT E) BINARY hi XEJ; 
 DECLARE STATE -UNARY FIXED; 
 ACTUAL_ARGl=E\MH ARG1) ; 
 *CTUAL_Ai?G2 = EVAL( ARG2 ) ; 
 It rYPE_UFl ACTUAL_ARG1) =*J 
 £ TYPl"_UF( AC TUAL_ARG2 ) = $D 
 £ TYPE_OF( ARG3)=$R 
 £ IS_C 1 RECTI UN! ATTR_QF 1**^,1) ) 
 IHcN DC; 
 
 Nlw_CGNSTI TUEnT=MLTS( ACTUAL_ARC1 , aCTUAL.aRuZ ) ; 
 
 cNC 
 
 RE IUR\l( ALTER! NAiME_IN( ARG3) , 
 
 INSERT! ATT R_UF(ARG3) tNEW_CiiNST I TUE^Ti 
 *FS_NAMLD(NAME_IN< Aftii3l ) ), 
 
 bTATL) ) J 
 END; 
 CALL ERK_1SG( 
 
 •AN ARG GR AN ACTUAL_ARG IN MLT Ii MU GJCC); 
 RtTURN! UNJEF I NED) ; 
 V L f; 
 
 J I v:PRJC ED LPE! STATE) b I NARY FI Afcu; 
 
 JFCLARE STATE dINARY FIXlD; 
 ACTuAL_/- v PGl=tYAL! ARGL) J 
 ACTUAL_ARG2=EVAL< ARG2J ; 
 If TYPE_CF( At TUAL_ARG1 )=$U 
 £ f YPF_uF ( ACTUAL_ARU2 ) =AJ 
 
23 
 
 £ TYPE_OFl ARG3)=tR 
 ti 1S_UIRECTIGN!ATTR_0F!ARG3) ) 
 THEN DO; 
 
 IF NUMb_INCACTUAL_ARG2)-i=0 
 
 THEN DU; 
 
 NE*,_CONSTITUENT = Dl VS! ACTUAL_ARG1 , aCTUAL_ARG2 ) ; 
 
 RETURN! ALTcR(NAME_Ii\l! ARb 3) , 
 
 INSERT! ATT R_GF!ARG3) ,NEW_CONST ITUENT i 
 WFS_NAi4LU(NAML_IN( ARG3) ) ), 
 bTATE) ) ; 
 ENID; 
 CALL ERR_MSG! ' ACTUaL_ARG2 IN OIV IS • ); 
 RE TURN ( UNO EF IiMEO) ; 
 END; 
 CALL ERR_MSG< 
 
 •A\ ARG UR AM ACTUAL.ARG IN DIV IS Nu GOUl) 1 ); 
 RETURN ( UNDEF INFO) ; 
 ;ND D I V; 
 
 4NU: PROCEDURE { STATE ) olNARY FI XcU; 
 DECLARE STATt BINARY rlXED; 
 ACTUAL. ARG1=EVAL< ARGl) ; 
 ACTUAL_ARG2=EVAL( ARG2) J 
 IE TYPE.JfM AC TUAL_ARG1 ) =iri 
 £ 1YPE_GE I ACTUAL_ARG2 ) = 4B 
 £ TYPE_JF( ARG3) =tR 
 £ IS_L)IRLCT10N( 4TTR_UF(ARG3) ) 
 THEN DG ; 
 
 NL^_CJNSTI TUENT=ANJS{ AlTUAL_ARG1 , ACTJAL_ARG2 ) ; 
 
 END 
 
 RETURN! ALTER! N|AME_I N ( AKG3 ) , 
 
 I NISERT! ArTR_OF ( AkG^ > ,NEW_CUNST1 TUEMT , 
 WFS_NAMbL>l*AME_I \! ARG3) ) ) , 
 STATE) ) ; 
 END; 
 CALL ERR_MSG( 
 
 •AN ARG uR An ACTUAL_ARG IN AND IS NU GOGD* )J 
 RE rURN( UN JEF INED) ; 
 AND ; 
 
 UR :PRUCEDUrE ( STATE) BINARY FIXED; 
 DECLARE STATE BINARY FIXED; 
 ACTUAL. ARG1=EVAL( ARG1J ; 
 
 ACTUAL_ARG2=EVAL( ARG2) ; 
 IF TYPE_i]F( ACTUAL.ARG1 ) =Sb 
 £ TYPE UF! ACTUAL ARG2)=i>B 
 
24 
 
 £ TYPt.OF ( ARG3) = 4R 
 6 I S_D I RECTI ON I A TTR_OF ( ARG3 ) ) 
 THuiM DG ; 
 
 NF w_CJNSTl ruENT= uR^>( ACTJAL_ARG1 » ACTUAL. ARG2 ) ; 
 
 Kb TURN! ALTER! NAME_IN( ARG3) , 
 
 INSERT! ATTR_UF(ARG3) , NEW_CUiNST 1 FUENT , 
 WFS_NAMED(NAHE_IN( ARG3) ) I, 
 STATE) ) ; 
 END? 
 LALL ERK_MSGl 
 
 •AN ARG OR AN ACTUAL_ARG IN OR IS NC GOOD')! 
 Rt TURN( UNDEF INE J) ; 
 END CR ; 
 
 vJUT :PKUCECLF E ( STATE )b I NARY FI XEO; 
 JFLLARE bT4TE alNARY FlXcUJ 
 AC rUAL_ARGL=E VAL( ARG1 ) ; 
 lr rYPLjJF ( AC TlUL_AKGl ) = Sti 
 £ TYPE_OF( ARG2>=*R 
 (n I S_L>IREC riLilM(A rTRJJF ( ARG2 ) ) 
 THcN DC; 
 
 NEw_CJ v* S T I ruE,4T ='MJ Ti> ( ACTJAL_ARG1 ) ; 
 
 RE TU* \l( ALTER ( NAME_I N( ARG3 ) , 
 
 I.MSERn AFTR.GFI AKG2 ) ,NEw_CuNST I T JENTi 
 WFS_NAMfcD(NAME_lN( A*S2) ) ) , 
 bTATc) ) ; 
 END; 
 CALL EhR_MSG( 
 
 •Ai\ ARG UK A,\ ACTUAL_ARG IN MOT IS NO GOOD 1 ); 
 RE TURN 1 CN ObFINEO) ; 
 END T.CT; 
 
 CONC:PRUCtUCPb( STATE) hlNAKY EIXEO; 
 JECLARI STATE 3INAPY FIXED; 
 IE TYPF_JF(APG3) -. = *R 
 
 I -.IS.OlRcC TIOiNi ATTR_OF {ARG 3) ) 
 THE, [)U; CALL ERk_MSG( «ARG3 IN CuNC IS IMJ GUOD')! 
 RE TUR\( J.«*:)lE InED) ; 
 END ; 
 ACTLAL_AKG1=EVAL( ARGll ; 
 AC rUAL_ARG2=E VAL ( AKG2 ) ; 
 IF T YPt.UF ( AC TUAL_AKG1 ) = $.j 
 S 1 YPt_ JF ( aCTUAl_AKo2 ) = iB 
 ThEi\ 
 
25 
 
 NEW_CUNSTI TUENT=CGNCS_BITS(ACTUAL_ARG1 t 
 
 ACTUAL_ARG2); 
 
 ELSE DO; 
 
 IF TYPE_UF(ACTUAL_ARG1) =$C 
 t» TYPi-_JF( ACTUAL_ARG2)=$C 
 THEN 
 
 NE*_CUNSTITUE.\IT=CUNCS_CHRS( ACTUAL.ARbl , 
 
 ACTUAL_ARG2); 
 
 ELSE DO;CALL ERR_MSC( 
 
 •ACTUAL_ARG1 UR ACTUAL_ARG2 IN CJNC IS iMU GUOU* ) J 
 
 RETURM UNDEFINED) ; 
 END ; 
 END; 
 RETURN (AL1 ER ( UAME_IN( ARG3) , 
 
 I \|SERT<ATTR_UF(ARG3) , NE»%_C u\iST I TUEhT , 
 WFS_NAMED(NA«E_I M( ARG3) ) ) , 
 STATE) ) ; 
 END CLNC ; 
 
 SPL T:PRCCEDURc( STATE )bl NARY F IXED; 
 DECLARE STATE rtlNAKY FIXED; 
 IF TYPE_OF(ARGl)=$R 
 6 I S_UlRECTIUNl AT TR_UF< ARG1 ) ) 
 L TYPE_UF I ARG2) =*R 
 C I S_DIRECTlU\i( ATTR_UF{ ARG2) ) 
 THEN DO; 
 
 ACTJAL_ARG1=CJNSTI TUE NT_AT( ATTR_ JF ( ARol ) , 
 
 WFS_v|AMEJ( NAME_IN( ARG1 ) ) ) ; 
 IF TYPc.JF ( ACTUAL_ARG1 ) =$13 
 THE i RE TURN (ALTER! NAME_IN( ARG2) , 
 
 INSERTt ATTR_uF(ARG2) , 
 SPLIT_ciITS2( AlTUaL_AkG1 ) , 
 
 WFS_NAMED(NAV,E_IN( ARG2 ) ) ) , 
 ALTER(NAME_1N( ARG1 ) » 
 
 CHANGE! ATTR_OF(ARGl ) , 
 SPlI T_B ITS 1( ACTUAL. AKGl ) t 
 
 WFS_NAMEU(NAME_IMARG1) ) ), 
 STATE) ) ) ; 
 IF TYPE_l)F( ACTUAL_ARG1) = *C 
 THEN RE TURN I ALTER (NAME. I N< ARG2) , 
 
 I \ISERT( ATTR_OF IARG2 I, 
 SPLI T_CHRS2 { alTUAL_ARG1 ) , 
 
 WFS_NA,MED( NANE_IM ARG2 ) ) ) » 
 ALTER(NAHE_IN< ARG1) » 
 
 CHANGE! ATT k_OF( ARG1 ) , 
 SPLI T_CHRS1 ( ACTUAL_ARG1 ) , 
 
26 
 
 rfFS_NAMED(NA.ME_IN(.ARGl) ) ), 
 
 STATE) ) ) ; 
 CALL ERR_MSG( • ACTUAL_ARGL IN SPLT IS NO GOOD' ) S 
 
 RtTURN(UNDEFlNED) ; 
 END ; 
 CALL bRR_MSG( 'ARG1 OR ARG2 IN SPLT IS 4C GOOD 1 )! 
 RcTURNdJNOEFINEDJ ; 
 END S^LT; 
 
 TtST : i j hOC(:lL^( 
 J E C L A * E b T A 1 E d 
 DECLARE CC'PARI 
 
 ( 
 
 ST ATblJ 
 INARY r 
 SUN_MUU 
 
 • = • 
 
 • >= • 
 
 • =A • 
 i 
 
 INAKY FIXED; 
 
 I xcu ; 
 
 E TAcJLcl22) CHARACTERS) INITIAL 
 
 •A 
 •A 
 •T 
 
 -A • 
 
 > ' t 
 
 - = A« , 
 
 A-.= ' , 
 
 A-. = A» , 
 
 r-i=A« , 
 
 • < • 
 
 • = j • 
 
 •T = ' 
 
 •A = T« 
 
 ■T =T« 
 
 • <= • 
 
 1 -=T« 
 
 • T- = • 
 
 • a-.= r » 
 
 • r-isT 1 
 
 ) ; 
 
 UECLAR 
 CfcCLAS 
 ACTUAL 
 ACTUAL 
 ACTUAL 
 If TYP 
 THEN C 
 C 
 
 I 
 
 T 
 E 
 CALL E 
 Rfc TuRN 
 TEST1 : 
 IE I<=t 
 IF TYP 
 
 then i 
 
 T 
 
 E CJMPARISON__MQJE CHARACTERS); 
 £ TET BIT( 1 ) ; 
 _AAG1=EVAU ARG1 
 _ARG2=EVAL( ARG2 
 
 _A4G3=EVAL(A4G3 
 F_JF ( ACTUAL_A.<i, 
 
 heck.cumpakFscn 
 
 CMPARI SUN_M'J,)t- 
 U 1=1 TO DIMICu 
 E Cu.MPARISUN_MU 
 HE.Ni GOTO TEST1 ; 
 NO CHFlK_LOMPAR 
 
 rr.msui 'compar1 
 
 (undef ined» ; 
 
 ) ; 
 ) ; 
 ) ; 
 
 2 ) =$C 
 .MODE: DO; 
 
 CHARS_Ii\l( ACTUAL_AkU2 ) ; 
 .-PARI SON.MODE.TAdLEi 1) ; 
 
 DE=CLMPARlSCN_KuDE_TAbLE( I) 
 
 I SON.MuDE; 
 
 SJ,m_MUJE IN TCi>T lb NO GUUD 1 ) ; 
 
 N DO; 
 (ACTUAL 
 
 THE 
 E_UF 
 c; 
 bT=TESTS( I , 
 
 .AKG1 ) =TYPE_OF( ACTU*L_ARG2) 
 ACTUAL.AR31 , AC Tu AL_£ RG3 ) ; 
 
 GuT'j TdST2; 
 END ; 
 TLST.LNDEFINED: 
 
 At. TURN ( ALTER (EXEC (STATE ) , 
 
 SE T_SC A:\INER_ATTR (uMJtF IN, 
 
 CONTCNT.OF.EXECISTATE) ) , 
 STATc) ) ; 
 
 IF I<=K 
 
 END 
 THEN 
 
27 
 
 00; IF TYPE_0F( aCTUAL_ARG1)=SC 
 THEN GOTO TEST3; 
 ELSE-GO TU TEST_UNDEFINED; 
 EMD; 
 
 IF I<=14 
 
 THEN QGjIF TYPE_OF ( AC TUAL_ARG3 ) =*C 
 THEN GOTO TEST3; 
 ELSE GOTO TEST_UNDEFINtD; 
 END; 
 TEST3: 
 
 TET=TESTSU ,ACTUAL_ARGl , ACTUAL. A RG1 ) ; 
 TEST2: 
 IF TET 
 THEN RETURM ALTER ( EXEC {STATE) , 
 
 SET_SCANNER_ATTR (SUCCESS, 
 
 CUNTENT_OF_cXEC I STAT c) ) , 
 STATE) ) ; 
 RETURN( ALTER! EXEC (STATE) , 
 
 S£T_SCANNtR_ATTR( FAILURE* 
 
 CGNTENT_UF_EX EC (STATE! ) » 
 STATE) ) ; 
 ENO TcST; 
 
 EVAL: PRGCEOUPtt ARGIdlNARY fUhO; 
 JECLARE ARC BINARY F1XE0; 
 IF TYPt_OF(ARG) = i>R 
 
 & I S_D1 REC T I 0,M( AT TR_OF{ A RG) ) 
 THEN RFTJRiMl CONSTI TUE N T_A T ( ATTR_OF (ARG) , 
 
 irfFS_NAMEU(NAME_IN( A KG) ) ) ) ; 
 RE TORN! ARG) ; 
 ENC EVAL; 
 
 END NUCLFQL; 
 
23 
 
 3. 
 
 NUCLECJL PROGRAMMING LANGUAGl AS A MUDEL l-Ok MUCLtUL 
 
 ivlUlAT IUim : 
 
 SET OF ALL STRINGS OVER 
 
 <A> DENUTFS A SUBSET UF THE 
 
 ALL KEYPUNCH SYMBOLS i 
 <A*> ::= <A> | <AXA*> ; 
 <A*?> : : = <A*> | <EMPTY> ; 
 <A,1> DENOTES AN ELEMENT Oh <A>, 
 
 I MAY BE SJbSTITJTEO BY A POSITIVE 
 <A*,I> DENOTES AN ELEMENT UF <A*> ; 
 <A*?,I> DENOTES AN ELEMENT UF <A*?> ; 
 
 INTEGER 
 
 DEFINE JAM TO BE THE UNION UF THE SET OF ALL STRINGS 
 OVER ALL KEYPUNCH SYMBOLS AND FINITE CULLECTIUNS OF SUCH 
 S F R I N G S J 
 
29 
 
 3. I. 
 
 NUCLEOL PROGRAMMING LANGUAGE SYNTAX 
 
 <WFS> ::= <BLJCK WITH SCANNER> I <$SXBLOCK> | <$S> 
 <BLGCK WITH SCANNER> ::= <*< XBLOCK*?XiSXtiLUCK*?X$ »> I 
 
 <${XBLGCK*?XBLGCK wl TH SCANNfcRXBLljCK*?X $ ) > 
 <BLUCK> ::= <JRL)INaRY CJNSTITJENT> | <*(X3LUCK*?XJ» )> 
 <CUNSTITUENT> ::= <l)RD I NAR Y CUNSTITUENT> I 
 
 <*(> | <i)> | <$S> 
 <URUlNARY CCNSTI TUENT> ::= <$B> j <$C> I <bo> 1 <$P> | <$l 
 
 <$C> 
 <iC> 
 <iP> 
 
 <.$R> 
 
 $d<BA> , <BITSTRl!\lG>' 
 
 IC<C A>« <CH AR AC TER STRINGS 
 
 $D<DA> , <NUMbER>» 
 
 $P <T A>« <CH Ak AC TEP STRINGS 
 $R<.RA>'<wFS NAME>« 
 
 <i( > 
 OS> 
 
 = $(<P\> 
 = $ X P A > 
 
 = $S<SA>»<Wf-S 
 
 .\IAMF>» 
 
 <HA> 
 <U) 
 <HA> 
 <1 A> 
 <RA> 
 <PA> 
 
 <SA> 
 
 <6LA \JK> 
 <BLAxK> 
 <BLANK> 
 <BLANK> 
 <BLANK> 
 <H LA.nIK > 
 
 AND 
 D | F | N 
 
 I M I S 
 
 I 3 I R 
 
 I N 
 
 CuMB IiNiAT I ONS 
 I S I U 
 
 UP 
 
 t » 
 
 X 
 
 N, 
 
 S» ANO J 
 
 <bITSTRI\G> : 
 < H I T > : : = r . | 
 <CHARACTERSTR 
 <CH£RACTFR> : 
 <BLANK> ::= A 
 <KtST> ::= . 
 
 = <dIT*?> 
 1 
 
 NG> 
 = < 
 
 SIN 
 < 
 
 :bl 
 
 .L 
 
 I / I , 
 
 <LETTER> ::= A | 
 
 I M I 
 
 I Y | 
 
 <OIGI 
 <NUMB 
 < W f- S 
 
 T> : : 
 GR> : 
 
 NAMt > 
 
 = < 
 
 I 1 
 DIG 
 
 SF 
 RE 
 TH 
 
 I 
 I 
 
 b 
 i\ 
 Z 
 I 
 
 I r 
 ou 
 
 ol 
 
 EN 
 
 := <CHARACTER*?> 
 
 ANK> | <<EST> | <LtTTFR> I <DlGiT> 
 
 c SPACE 
 
 I I H I U I $ I * I I I i I i 
 «l_l>l?J:|*lcJ| 
 ICIUIEIFIGIHJI 
 I U J" P I Q ] R | S | T j U 
 
 • I = 
 I J I 
 
 I V I 
 
 2 I 3 | 4 | b I 6 
 *> I *<L)IGIT*> I -< 
 
 tNCfc OF LtTTEKSt DI 
 NNING WITH LETTER A 
 B CHARACTERS. 
 
 OIC 
 GI7 
 
 NO 
 
 1 T 
 S, 
 
 NO 
 
 3 I 9 
 
 AND 
 T LUNbF.R 
 
 <INSTRUCTIGN> : 
 
 = <MUVE> 
 <XVRT> 
 <AND> I 
 < FE ST> 
 
 I <CUPY> | <SHFT> | <RSTR> | 
 I <AU0> | <SUB> I <MLT> | <DIV> 
 <OR> | <NOT> | <CUNC> I <SPLT> 
 
 <MUVC> ::= tCK'HOVF. ■ ( <SKXSR> | <WRXWR> ) 
 
30 
 
 <C()PY> ::= $CK'CUPY« ( <BI_UCKXSk> 
 
 <SR> <WR> I 
 <WK> <WK> ) 
 <SR> 
 
 ( <sk> l__<wR> 
 
 i <T/A> | <5K> 
 
 <ShFT> 
 
 <RSTR> 
 
 <CVKT> 
 
 <AUU> 
 
 <SUB> 
 
 <ML T> 
 
 <ni v> 
 
 <Ai\u> 
 
 <uR> 
 
 <NuT> 
 
 <CCi\C> 
 
 <5PLT> 
 <TEST> 
 
 $CK «SH 
 
 = $CK'R 
 
 $CK'CV 
 
 $CK«aDD 
 
 JCK'SUD 
 
 iCK «MLT 
 
 *CK«DIV 
 
 iCK'AUL) 
 
 $CK'l)R' 
 
 iCK 'NUT 
 
 tCK'CJ 
 
 SCK'Cu 
 
 ICK'SP 
 
 1CK' Ttf S 
 
 ( <TES 
 
 ( <ib> 
 
 FT' 
 
 STR 
 
 RT 
 • 
 
 NC 
 
 LT 
 T« 
 
 T MUDE> 
 
 <$0> 
 <$J> 
 <$.)> 
 <$L)> 
 
 <$B> 
 
 ( <*B> 
 
 ( <uc> 
 <SR> <$R> 
 <t>b> | <*C> 
 <SR> ) 
 
 <SR> 
 
 <SR> 
 
 <SR> 
 
 <i>R> 
 
 <SR> 
 
 <SR> 
 
 <SR> 
 
 I <SR> 
 
 I <SR> 
 
 ) ( 
 
 I ( 
 
 ) ( 
 
 ) ( 
 
 ) ( 
 
 ) ( 
 
 ) 
 
 )_ 
 
 ) <SR> 
 
 <$L)> 
 
 <$D> 
 
 <$D> 
 
 <$D> 
 
 <$B> 
 
 <$B> 
 <SR> 
 ) ( <$b> 
 ) ( <$C> 
 
 <SR> 
 <SP> 
 <SR> 
 <SR> 
 <SR> 
 <SR> 
 
 <SP> 
 <SR> 
 
 <SR> 
 
 <i>R> 
 <SR> 
 
 <SR> 
 <SR> 
 <SR> 
 
 ) <SR> 
 ) <SR> 
 
 j <$D> I <$P> | <SK> ) 
 
 I <$P> | <bR> ) 
 
 <SP> ::= *RL'<WFS NA.1E>' 
 ^k> ::= fR «<WFS NAME>« 
 
 | JRR'<wFS NAME>« 
 
 < T Y P t > 
 <T/A> 
 
 <TfST 
 
 ML'Dt> : 
 
 Li | C I 
 iC'3/<iiA>« 
 tC • R/<RA>' 
 
 iC /<3A>' 
 /<RA>' 
 = $C 
 
 >c 
 $c 
 
 iC 
 
 $c 
 $c 
 
 P I R I S 
 *C 'C/<CA>' 
 IC« ( /<PA>' 
 iC /<CA>« 
 iC • /<PA>' 
 
 <= • 
 
 = A ' 
 = T« 
 = A • 
 = T« 
 = T« 
 = A ( 
 
 ( I ) 
 $C'l)/<l)A>' 
 %C* )/ <P\>> 
 /< ( JA>' 
 
 I *C 
 
 $c 
 
 iC 
 fcC 
 
 tc 
 
 > • 
 
 -.-A' 
 
 A-. = A« 
 
 A- = T' 
 T-i = T» 
 T-. = A« 
 
 fcC 
 
 I iC'P/<rA>« 
 
 I iL 1 /<TA>' 
 
 < 
 > = 
 
31 
 
 3.2. MAPPING OF NUC LEUL INTO NUCLEUL PROGRAMMING LANGUAGE 
 
 TU DEFINE AN INTERPRETATION OF NUCLEOL FORMAL SYSTEM 
 <ALPHABET, TERMS, FURMULAS> IN NUCLEOL PROGRAMMING LANGUAGE 
 I FIRST DEFINE A MAP a) ON ALPHABET AS FGLLOWS: 
 
 MAPS VARIABLES INTO THfc SET OF 
 /* JAN" WAS DEFINED IN 3. */ 
 
 VARIABLES RANGING OVER JAM; 
 
 d MAPS BASIC PREDICATES INTO THE SET OF SUBSETS OF JaM 
 JNICN THE CARTESIAN PRODUCT JAM X JAM 
 wHERE SOME OF THEM ARE DEFINED AS FOLLOWS: 
 
 a) IS STATE IS 
 
 DEFINtD TO Bt THE SET OF ALL FINITE COLLECTIONS 
 OF ELEMENTS OF <WFb> SUCH THAT: 
 
 1) THERE IS EXACTLY ONE <WF$»1> NAMED 
 <wFS NAM£»1> IN THE COLLECTION WHOSE 
 SCANNER <$S,1> = $S<SA, !>«<«FS NAME,1>' 
 HAS ATTRIBUTE <SA,1> = N | S | F | U . 
 
 2) NO PAIR <wFS,l> AND <W> i , 2> 
 
 IN THE COLLECTION HAVE SCANNERS 
 
 <$S t l> = iS<SA,l> , <wFS NAME,1>« 
 
 AND 
 
 <$S,2> = i>S<SA ,2>'<wFb \IAME,2>' 
 
 WITH <WFS NAME,1> = <WFS NAME,2> . 
 
 DENOTE THIS StT BY <STATc> 
 
 AND ITS ELEMENTS BY <STATb»l> 
 
 JIS_WFS = <wFS> ; 
 a)IS_BLUCK = <BLUCK> ; 
 jJIS.CUNSTI TUENT = <CuNSTlTUE 
 j) I S_ 1 Y P E =<TYPE> ; 
 aiS.DIRECTION = L 1 R ; 
 DIS_dITS = <BITSTkIMG> ; 
 JIS.CHRS = <CHARACTERSTRING> 
 i)IS_NUMB = <NUMBER> ; 
 dlS NAME = <WFS NAME> ;• 
 
 NT> 
 
 jj MAPS BASIC FUNCTIONS INTO THE SET UF FUNCTIONS 
 
 JAM X JAM X...X JAM > JAM 
 
 WHERE SOME UF THEM ARE DEFINED AS FOLLOWS: 
 
 -uEXECKSTATE, 1>) = <WFS NAME,1> UF THt SCANNER <$3,1> 
 
 CONTAINED IN THE UNlQUt <wFS,l> 
 IN <STATE,1> SUCH THAT 
 <SA,1> = F | N I S I U ; 
 
 iCCNTENTKwFS uAME , 1 > , <STATE , 1 >) = THE UNlJJE <WFS,1> IN 
 
 <STaTE,1> WHICH CUNTAINES J hh SCANNER 
 <iS,l>=$S<SA ,1 >'<wFS NAME,1>« ; 
 
o)CR 
 
 LL ( <WFS 
 EATE( <kF 
 
 -jBL 
 i)6L 
 
 i)CL) 
 
 i)Dt 
 DIN 
 
 oul N 
 
 i)Sh 
 
 tJRL 
 
 /* - AN 
 
 OF J 
 
 GCK_AT(fl 
 
 ULK_AT (K 
 
 NSI ITUEN 
 
 L t T E ( K , < 
 
 = < 
 
 S E R T ( R , < 
 
 < 
 
 = < 
 3L01R,. . 
 
 II- ! (R , . 
 STORE ( <a 
 
 NAME,1>,<STATL, 
 
 a)CUNTENT 
 
 S NIAi^tb , 2> t <WFS • 
 
 wHERc <W 
 
 EXCEPT T 
 
 OF <WFS, 
 D «■ ABOVE UE.MOT 
 IFFERENCE AND U 
 ,<$( ,1XBL0CK*? 
 
 <$) ,1> ) 
 , <iS,l XBLGCK, 1 
 
 - <BLUCK 
 T_AT(K, ...<tbt 
 
 = <CJiMSl 
 *( ,IXBLGCK*?,1 
 <M , IXBLOCK* /, 
 BLJCK,2>, 
 t( ,1XBLUCK*?, 1 
 i( ,1XBL0CK*?,1 
 . <*< , 1XORDINAK 
 
 <ORDlNAK 
 <i( , IXORDINAP 
 
 <UROI nIAR 
 
 . . <tS» lXCLiNSTI 
 
 = ... CCUNSTi 
 
 FS,L>) = <SS,1> 
 
 32 
 
 1>) = <STATbtl> - 
 
 (<WFS NAME,~1>,<STATE, 1>> ; 
 
 l>,<STATEtl>) = <STATh,l> ♦ 
 
 <wFS,2> 
 FS,2> IS IDENTICAL TU <WFS,1> 
 HE <rtFS NAMEfl> IN THE SCANNER 
 1> IS REPLACED BY <WFS NAME,2> ; 
 E THE SET THEURETICAL OPERATIONS 
 NION */ 
 »lXiS tlX BLOCK, IXBLOCK*?, 2 > 
 
 = <BLGCK,1> ; 
 >) - aMLOCK_AT(L,<$S, lXdLJCK, 1>) 
 
 »i> ; 
 
 1 XCGNSTITUENT,1>. . . ) 
 
 1 ruENT,l> ; 
 
 X*S,lXLlLOCK,2XBL<JLK*?, 3X4 )tl>) 
 1 XiS ,1XBLUCK*?,3XS) , 1> 
 
 XiS,lXBL0CK*?,3XS) , 1>) 
 X>S,1XBL0CK,2XJL0CK*?, 3><$l 
 
 Y CONSTITUENT*?, 1X$S»1> 
 
 Y CGNS1 ITUENT*?,2X*» ,1> ... ) 
 
 Y CONSTITUENT*?tl> 
 
 Y CONSTITUENT*?, 2><tStlX»f l> 
 TUENT,1> ...) 
 TUtNT,lX$S,l> ... ; 
 <JLOCK,l> ; 
 
 i>; 
 
 ; i)SCAi\iNER__ATTR_Of=( ... *S<SA , 1 >»<WFS NAME,1>« ...» = <SA,1> 
 a)SFT_SLANNER_ATTR<<SA,l>, ... *b<SA, 2> • <WF S NAMfc,2>' ...) 
 
 = ... $S<SA,1> , <WFS NAME,2>« ... ; 
 
 JTYPfc.UF ( iOYPE ,1^ ... ) = <TYPE,1> ; 
 
 aJB ITS_IM SB<BA,1>«<BI TSTRl NG , 1>' ) = <b I TST R I NG , 1> ; 
 
 JChRS_IN( $C<CA, 1> , <LHAKACTERSTRING,1> 1 ) 
 
 = <CHARACTERSTRING,l> ; 
 i}NUM6_IN{ $C<DA, 1> , <NUMBER, 1>» ) = <NUMbEP,l> ; 
 i)NuMt-_ I,\< iK<RA, 1>'^FS NAMF,1>») = <WFS NAME,1> ; 
 
 j) MAPS CONSTANTS I NTU JAM AS FULLUWS 
 
 a)J>B = B 
 
 j)$L = C 
 j)tC = 
 Ji»P = P 
 J $ K = R 
 
 .JiLEF T_PARLNT = { 
 i)$k IGhl_PARFN T = ) 
 tJLEFT = L ; 
 
 ilKlGhT = R ; 
 
33 
 
 NEXT 3 IS EXTENDED, tiY NATURAL HCMOMORPHI S M , ONTO THE 
 SET UP TERMS INDUCTIVELY AS FULLUWS: 
 
 IF V IS A VARIABLF, THEN oJV IS THE IDENTITY MAPPING 
 F I V 1= W OF JAM ONTO ITSELF ; 
 
 IF C IS A CLNSTANT » 08C IS DEFINED AbOVE *, 
 IF T IS A TERM OF THE FORM 
 
 F(TL,... ,TM) 
 WHFRE F IS A iASIC FUNCTION AND Tlt«..»Ttt ARE TERMS i 
 THEN aT IS THE MAPPING 
 
 JP ( 3)Tl f . .. , i)Tri) 
 FROM JAM X JAM X...X JAM INTO JAM ; 
 
 LASTLY a IS EXTENDED ONTO THE SET Of FORMULA:* INDUCTIVELY 
 
 AS FOLLOWS: 
 
 IF A IS A FLRMOLA JF THE FORM 
 
 Tl =T? 
 WHERE Tl ANC T2 AkE TLR.mS , THEN J A IS THE PR JPOS 1 T 1 MAL 
 FUNCTION 
 
 a'Tl = JT2 
 WHERb THF • = ' ISA WEAK cQJAlITY Kb' LA Tl UN (SF^ 2.2.) 
 Jf_F INED ON JAM ; 
 
 IF A IS A FLPMOLA OF THE FuRM 
 
 Pi Tl ,. .. , TM) 
 WHcRE PISA iASIC PREDICATE AND Tli...,TM ARE TERMS r 
 THEN <3A IS THE PREPOSITIONAL FUNCTION 
 
 FOR OTHER FORMULAS THt FOLLOWING IDENTITIES HOLD: 
 
 j)( FORM1 | FORM2 ) = dhORrtl | «JFURM2 ; 
 
 til FORM1 E FORM2 ) = JFJRM1 | aJFURMZ ; 
 
 »{ FORM1 => FORM 2 ) = a)FORMl => aFORM2 ; 
 
 d>( iFURM ) = - JFURM ; 
 
34 
 
 *. THE NCCLEOL MACRO PROCESSOR \IUCrtAC 
 
 •1ACRC SYNTAX 
 
 <MACKU INSTRUCTION ::= iC M ' MNEMONl C>' <BLOCK*?> 
 
 <MACRO DEFINITION ::= *IXM <MACRO INSTRUCTION PRUTUTYPE> 
 
 <dl_OCK> $)XM 
 <MACP'l INSTRUCTION PUUTUTYPE> ::^ <${> SCM ■ <MNEi-1UN I C> ■ 
 
 <*P*?> <!»)> 
 <MNEMUN1C> ::= <CHARAC TcRS TRI NG> 
 
35 
 
 4.2. 
 
 NUCNAC 
 
 /* 
 
 NUCMAC 
 CALL BY T 
 WITH REPL 
 A MACKO D 
 BUT SINCE 
 CANNOT HA 
 
 ACTUAL 
 PARAMETER 
 COKRESPUN 
 OF THIS T 
 
 NUCMAC 
 INSTRUCTI 
 EVEN A SH 
 PKGGRAMMI 
 
 changes t 
 
 THE SE 
 
 IS A SIM 
 HE MACRO 
 ACEMENT 
 cF INITION 
 
 THERE IS 
 NDLE RECJ 
 
 PAR^METE 
 
 SPEC IFIE 
 DING ACTU 
 YPE. 
 
 CCNSISTS 
 ON St AND 
 CRT NOCLE 
 NG EASIER 
 A S 1 E R . 
 VEN WFS'S 
 
 ple macro processor. it replaces a macro 
 body of the correspond1 nt, macro definition 
 f formal parameters for actoal ones. 
 may in torn contain a macro call, 
 no conditional expansion feature* nucmac 
 rsive macros. 
 
 rs must bt single blocks. if a formal 
 s a type as its attribute, then the 
 al parameter must tit a single constituent 
 
 of seven wfs", approximately 1-j 
 approximately boo constituents. splitting 
 
 lIL PROGRAM INTO A NUMBER OF WFS'S MAKES 
 , DOCUMENTATION MORE LEGIBLE, AND FUTURE 
 
 UF NUCMAC ARE: 
 
 MAC PR INI 
 
 MACPRCTF 
 
 INU 
 
 MACRO 
 
 MACPRCAL 
 
 PARAM 
 
 MAC ERROR 
 
 :ThIS IS 1 
 AND I N I T I 
 
 : WHICH SCA 
 IT FINDS 
 FIR bT IT 
 
 :^HICH CHE 
 MACRO DEF 
 THE wFS 
 
 : AND THE.\1 
 
 : * H I C H BUI 
 ACTUAL PA 
 
 :AND 1NCLU 
 RETURNS C 
 F INALLY, 
 
 :NCT SPECl 
 ALL ERROR 
 
 ME WFS THROUGH WHICH NUCMAC IS ENTERED 
 ALIZtD. AFTtRUORJi. CONTROL IS GIVEN ID 
 NS THE PROGRAM TO BE EXPANOtD, AimD WHEN 
 A MACRO CALL TAKES APP^JPRIATb ACTION. 
 CALLS THE SHORT ROUTINE 
 CHS WHETHER THERE IS A CORRESPONDING 
 INITION, AND IF SO MAKES A COPY JF IT Ohi 
 
 FORMAL AND 
 
 ANU 
 
 ^IVbS CONTROL TO 
 LDS A LIST OF CORRESPONDING 
 RAMETERS ON THE WFS 
 
 DES THE MACRO bODY IN THE PROGRAM, 
 ONTROL TO MACPRCTR. 
 THERE Ij ASSUMED TO BE A wFS 
 FlfcD HERE, TU WHICH CONTROL PASSES 
 
 CONDITIONS. 
 
 UNDER 
 
 TFE FOLLCwINJ ASSUMPTIONS ARE MADE ON HOW NUCMAC 
 INTFRACTS WITH ITS ENVIROMENT. \\-\L PROGRAM TO BE tKPA^DcD 
 lb A aFS CALLED 'PROGRAM' . EACH MACRO DEFINITION IS A WFS 
 WHOSE NAME IS THE NAME JF THIS MACRO. NUCMAC RETURNS CJNTROL 
 TO A aFS CALLED 'SYS. ' . 
 
 Tht PRObRAM LISTING WHICH FOLLOWS IS ALSO INTENDED TO 
 SER\/E AS AN EXAMPLE Jh A NJCLbOL PROGRAM, AND HENCE IT IS 
 EXTENSIVELY ANNuTOTEO. COMMENTS ARE ENCLOSED BETWEEN THE 
 CHARACTER PAIRS •/*' AND «*/• , E.G. AS IN 
 /* THIS IS A COMMENT */ . 
 
36 
 
 $SN» MACRO INI 1 
 
 /* ASSIGNING TU THIS SCANNER THE ATTRIBUTE 'N« 
 4AKtS IT AN EXECUTION SCANNERf AND IS EQUIVALENT TO 
 DECLARING ITS wF S TO 6c THE MAIN PROCEUORE */ 
 
 4 { XMACPP IN I ■ 
 
 fcCK'COPY 1 $1 i< *) *) SRN'PARAfV 
 
 /* *FS PARAM IS OPENED CONSISTING UF EXTERNAL PAIR OF 
 PARANTESES WHICH AUTOMATICLY AbSuME THE ATTRIBUTE 'X*, 
 AND AN INTERNAL BLOCK IS INITIALIZED. 
 
 PAR AM WILL BE USED IN A STACK FAbUN TO BUILD AND STORE 
 LISTS OF CORRESPONDING rURMAL AND ACTUAL PARAMETERS. EACH 
 SUCH LIS1 IS ENCLOSED L^ PARANTtStS AND THEREFORE CONSTITUTE 
 A BLOCK. LIST OF ACTUALLY EXPANDED MACRO IS ALWAYS THE 
 RIGHTMOST, IE. THE TOP ONE a,^i A STACK. THIS STACK SETUP 
 ULO.JS FOR HANDLING OF NESTED MACRO CALLS. THE ALREADY 
 INITIALIZED EMPTY BLuCK SERVES AS A BOTTOM OF THE STACK. */ 
 
 ♦CK'SFFT* $RR«PARAM« 
 
 tCK'SHFT' SRR'PARAM' 
 
 /* SCANNER POSITION *AS INITIALISED BY SHIFTING IT INSIDE 
 THE INTERNAL BLOCK FROM OUTRIDE OF THE WFS PARAM. */ 
 
 IP •MACPRCTR* 
 
 /* CONTROL IS GIVEN TO MACPRCTR aHUSE SCANNER IS ASSUMtD TO 
 
 jf in a restored position */ 
 
 I ) x »MACPR ini • 
 
 b ( X •MACPRCTR' 
 
 /* THIS IS THE CENTRAL SCANNING LOOP. CONSTITUENT AFTER 
 CONSTITUENT IS CHECKED ON THE WF S PRuGRAM mNO APPROPRIATE 
 ACTION IS TAKEN. WHEN THE END OF PROGRAM IS RcACHEDi 
 CLNTROL IS GIVEN TO THc SYSTEM */ 
 
 /* SlNCC THL ACTION IN CaSE JF aN ERROR IN THE tXPANDED 
 PROGRAM IS NOT SPECIFIED YcT, CONTROL IS olVEN Tu MACERROK 
 IiM THIS CASE * / 
 
 /* MACRO CALL ? */ 
 
 /* CuNSTlTLENT WILL BE TtSTEO FOR TYPE 
 
 • M« DENOTING MACPO INSTRUCTION KtY WORO 
 
 
 And attribute 
 
 &CK«TEST' iKR'PROGRAM' J>C • T= • $C 'C 
 fc( S 
 
 iCK^TEST' $kR'pRuGRAM« i>C ' A= ' $C 'M' 
 
37 
 
 $(S /* YES, MACRO CALL */ 
 
 /* bUILD AN INSTRUCTION TO COPY THIS MACRO ONTU WFS MACRO. 
 
 TO DO THAT CONVERT THE MACRO NAME INTO REFERENCE CONSTITUENT 
 
 AND INSERT IT INTO A SKELETON INSTRUCTION UN WES I NO . 
 
 THIS TRICK IS USED IN PLACE OF INDIRECT REFERENCE , WHICH 
 
 WE DO NUT HAVE */ 
 
 *CK«RSTR« $R 'MACPRCAL' 
 
 /* SCANNEk WAS RESTORED TO THE POSITION OUTSIDE THE *FS 
 .MACPRCAL. NOTICE THAT NO DIRECTION WAS SPECIFIED IN THIS 
 CASt */ 
 
 iCK'RSTR 1 iRL'IND' 
 
 /* SCANNER WAS RESTORED 10 
 
 IN *HICH IT RESIDED 0^ THE 
 •L' FOP LEFT WAS SPECIFIED 
 
 THE LEFT PARENTESIS OF THE BLOCK 
 WFS INU . NOTICE THAT DIRECTION 
 IN THIS CASE. */ 
 
 iCK ■ ShFT ' 
 iCK 'MOVE • 
 
 $PR« IND' 
 
 tR 'bYS.FSL' 
 
 /* SCANNER WAS POSITIONED AT THE DOMMY FIkST ARGUMENT OF 
 THE SKELETON INSTRUCTION, AND THE ARGUMENT WAS CLEARED. */ 
 
 iCK'CCPY' iRK 1 PROGRAM 1 SRk'INO' 
 iCK'CVRT' J.C 'R/ ' SRR'INU' 
 
 /* MACRO NAME WAS INSERTED AND CONVtRTED INTO REFERENCE 
 TYPE CONSTITUENT THUS MAKING IT THE ACTUAL F I RST" PARAMETER 
 OF THE COPY INSTRUCTION TO dE EXECOTED LATER. */ 
 SCK'SFFT' iRL'IND' 
 
 /* SCANNER WAS POSITIONED rtEFOUE THE INSTRUCTION */ 
 
 *R 'IND' 
 
 /* CONTROL WAS GIVEN TO THE NEwLY CREATED INSTRUCTION 
 ON THE wFb IND */ 
 
 $ )N 
 $)FU 
 
 /* GET HERE IF IT WAS NOT MACRO uALL */ 
 
 /* FORMAL PARAMETER \ J *E SUBSTITUTED ? */ 
 
 iCK'TEST' iRR'PROGRAM* t»C •!' = • iC »P« 
 MS /* YES, PARAMETER LIST RESET */ 
 
 iCK'RSTK' SRL'PARAM' 
 
 i(N /* BEGIN OF PARAMETER ^EA.^CH LOOP */ 
 
 tCK'MOVE' *RR'PARAM' iRL'PARAM' 
 
38 
 
 /* PARAMETER LIST CONSISTS UF CONSECUTIVE PAIRS UF 
 CORRt SPJNDING ACTUAL AND FORMAL PAnAMETEkS. SCANNER WAS 
 JUST POSITIONED BETWEEN THt ACTUAL »ON THc LcFT, A NO 
 FuRPAL, CN THE RIGHT , PARAMETERS. */ 
 
 $CK l TESr« tPR'PROGRAM 1 iC • = • *RR»PARAM' 
 
 /* CORRESPONDENCE BETWEEN FORMAL PARAMETtRS IN MACRU BODY 
 AND IN PARAMETER LI^T WAS CHECKED */ 
 
 t ( F L /* NUT THIS PARAMETER YET */ 
 
 iCK'SHFT* $RR'PARAM« 
 
 /* PUSITICN SCANNER AT THE NEXT PAIR CF PARAMETERS */ 
 
 * )N 
 
 /* IE PARAMETER NOT FOUND GO BkCK TU THE BEGINNlNb UF THE 
 ^tAPch LOOP. OU NOT CRObS THIS SOCCESFOL PAPENTcblj 
 BECALSt YCC ARE NOW IN NFUTKAL STATE *'/ 
 
 Mb /« 00 OUTSIDE THROUGH THIS PARENT «HEN PARAMETER 
 FOUND */ 
 
 pCK'MOVC 1 JRR'PRGGRAM* »R •SYS.FSL' 
 
 pCK'CGPY* $RL'PARAM' tKL'PRUGRAM* 
 
 /* PAKAMEIER S03STIT0TI0N wAS JUST MADE *•/ 
 
 *CK'RSTk« $R •MACPRCTR* 
 
 /* F.ivJ OF THE BRANCH. RESTORE THc SCANNER TO THE BEGINNING 
 
 JF THt CENTRAL SCANNING LOUP. */ 
 
 i. )N 
 
 /* END 01- PACRO BODY foARKE* ? */ 
 
 dCkMFST' tRR'PROGRAM 1 $C • = • pCS'ENuBOOY* 
 
 /* Thl bYbTtM MARKER •E^UBGDY' IS PLACEo AT THE ENJ OF 
 
 MACRO BODY WHEN MACRO BODY IS INCLUDED IN PROGRAM BY 
 
 MACPkLAL */ 
 
 i(S /* WIND UP THIS MACRO EXPANSION */ 
 
 •CK'MCVF* iRR'PROGRA^' $K •SYS.FSL' 
 
 /* ENDJODY MARKER WAS REMOVED */ 
 
 *C\'RSTr<« *RL«PARAM« 
 
 kCK ' ShF T • ikL 'PAR AM' 
 
 iCK'MOVE' iRR'PARAM' J>R • SYS.FSL 1 
 
 /* THE TOP PARAMETER LIST IS JELETED FRuM THE STACK*/ 
 
 bCK'SHFT 1 iRL'PARAV.' 
 
 /* ThL LAST INSTRUCTION mS TJ Re INSTITUTE PROCESSING OF 
 
 \ PKcVlOOS KACKO LiR IF NONE » PLACES THc SCANNER IN k FIRST, 
 UUMMY BLOCK */ 
 
 &CK «R 5Tr » ik MACPRCTR 1 
 
39 
 
 /* ENO OF THIS BRANCH, RESTORE TO THE BEGINNING OF THE 
 CENTRAL SCANNING LOOP */ 
 
 i IN 
 
 /* END UF PROGRAM TO bE EXPANDED ? */ 
 
 SCK'TEST' $RR 'PROGRAM 1 $C » T= ' $C •)■ 
 
 *{ S 
 
 iCK'TEST' $RR' PROGRAM' tC *A = ■ $C »X' 
 
 $( S 
 
 /* RHIGHT PARENTISIS WITH AN ATTRIBOTE X WAS MET, IT 
 
 4EANS END OF PROGRAM */ 
 
 *R 'SYS.' 
 
 /* CCNTRGL IS RETURN TJ SYSTEM */ 
 
 i )N 
 
 i)FC 
 
 /* GFT HtRE WHEN IT IS MUT THE tNJ OF PROGRAM */ 
 
 j.CK'bFFT' tPR 'PROGRAM' 
 
 /* LEAVE IHIS CONSTITUENT ALONE AND SI ART CHECKING THE 
 NEXT, IE. CLOSE THE CENTRAL SCANNING LOOP */ 
 
 /* THIS RETURN TO THfc BEGINNING OF THE CENTRAL SCANNING 
 LOUP IS DCNE 4UT0MATIcLY SINCE THE EXTERNAL PARENTES1S, 
 THE CNF WITH THE ATTRIbUTF 'X' , CANNOT BE CROSSED'*/ 
 
 $ IX'MACPRCTR* 
 
 $( X'l 
 /* 
 
 ♦ SUM 
 /$ 
 
 $CK 
 
 % 
 i )N 
 SR 
 $ IX • I 
 
 NO • 
 THI 
 THE 
 FOu 
 ARG 
 MAC 
 MOD 
 NEC 
 
 m • 
 
 INI 
 THE 
 •CO 
 
 R • 
 
 S IS A MOOYFIABLE PROCEDURE WHICH MAKES A COPY OF 
 
 MACRO DEFINITION CORRESPONDING 10 A MACRO CALL 
 NC BY MAGPRCTK JNTO THE WFS MACRO. THE FIRST 
 
 OMENT OF THE COPY INSTRUCTION BELG* IS SLT l>Y 
 
 PRCTR. IF NJCLEOL ALLOWED INDIRECT ADDRESSING, A 
 
 YFIABLc PROCEDURE SUCH AS THIS WOULD NOT BE 
 ESSARY */ 
 
 ENDED INITIAL POSITION OF THE SCANNER IS INSIDE 
 
 kFS */ 
 PY' >R 'DUMMY 1 i>R 'MACRO' 
 /* HQ MACRJ WITH THIS NAME cXISTS */ 
 
 MAC ERROR' 
 
 •MACPRCAL ' 
 
 NT 
 
40 
 
 > ( X'MACPRCAL' 
 
 /* INITIALISATION 
 
 /* MACRO WHICH IS 
 
 OF MACku CALL */ 
 
 CALLED WAS ALRtAOY CUPIED ONTU WFS 'MACRO' 
 */ 
 
 iRR • PARAM' 
 
 $PR 'PARAM' 
 $R 'MACRO' 
 iRR 'MACRO' 
 $RR 'PARAM' 
 iRR 'PROGRAM' 
 /* MACRO NAME 
 
 $RR 'PARAM' 
 
 *C 
 NO 
 
 .000 
 
 IRR' PARAM' 
 
 */ 
 
 JY 'INC 
 
 >CK 'KSTR ' 
 
 iCK • SFET ' 
 
 tCK'.iSTR' 
 
 J>CK • -10VE' 
 
 iCK • SHi-T • 
 
 iCK • TEST • 
 
 MFC 
 
 $R ViACEkftDR' 
 
 6)N 
 
 MS /* GEvltRATE PARAMETER LIST 
 
 tCK'.yjVC' fRk'PARAM' $R 'SYb.FSL' 
 
 SCKMGVfc 1 tkR'PROGRAM' $K 'SYS.FSL' 
 
 iM /* END OF PARAMETER LIST ? */ 
 
 iCK'TtbT' SRK'PARAM' $C »T= ' $C ')' 
 
 i(FL /* LuOP ON FORMAL PARAMETERS */ 
 
 /* CHECK IF THE TYPE uF ACTUAL PARAMETER IS A DESIRED ONE */ 
 
 iCK'TEST' IRR'PRUGRAM' tC »T = A« IRR'PARAN' 
 
 »(S /* SFT CORRESPONDING ACTUAL - FORMAL */ 
 
 1CKMGVF' iRk'PROGRAM' iKL • PaRAM' 
 
 tCK'SHFT 1 IRR'PARAM' 
 
 i )N 
 
 MHO /* TYPES DO NOT MATCH */ 
 
 IR'MACERRGR' 
 
 fc-)N 
 
 » )N 
 
 /•■ : CLOSE Tht LOOP TO NEXT PAKAME1ER */ 
 
 i ) S /* EXIT HERE WritN ALL FORMAL PARAMtTEKb PROCESSED */ 
 
 /* bET MARKER 'ENDBuDY' ANU IMCLOJE MACROBOOY INTO Tt\t 
 
 • PROGRAM 
 *CK 'COPY 
 i.CK 'kSTr 
 »CK ' SHFT 
 iCK 'MOVE 
 iCK 'MOVE 
 SCK • SHF T 
 /* CUMROL 
 
 , KILL 'MACRO' */ 
 SCS'ENDBODY' »kk'PkUGRAM' 
 IRR 'MACRO' 
 tkR 'MACRO' 
 
 ikk'MACRU' IRR'PROGRAM' 
 iR 'MACRO' 1ft 'SYS.FSL 1 
 iRR 'PROGRAM' 
 LUCK TO THE CENTRAL SCANNING 
 
 LOOP 
 
 iR 'MACPRCTR' 
 i>)N 
 
 $ ) X 'MACPkCAL' 
 
in 
 
 5 • CONCLUSION 
 
 The main conclusion obtained from this research is 
 that it is feasible and useful to combine the formal definition 
 of a programming language with its implementation. Specifically, 
 if this definition of NUCLEOL is augmented by programs which 
 implement the basic functions and predicates listed in 2.1, it 
 constitutes an interpreter for NUCLEOL. While these programs 
 depend on a particular realization of NUCLEOL (host computer, 
 data representation, etc.), a significant fraction of the 
 interpreter (about half) is machine independent. Hence, as a 
 by-product, we have considerably reduced the problem of trans- 
 ferring NUCLEOL from one computer to another. 
 
 The main task which was left undone is to use the 
 system of axioms which relate the basic functions and predicates. 
 While these axioms serve an intuitive purpose of explaining what 
 particular basic functions and predicates are, they have not been 
 used in the formal development. A challenging future development 
 would be to prove that they are consistent and complete, the 
 latter in the sense of defining NUCLEOL uniquely to a user. 
 
k2 
 
 REFERENCES 
 
 1. Naur, P., et al., "Revised Report on the Algorithmic 
 
 Language ALGOL 60", Computer J. 5, h, pp. 3^9-368,. 
 January, 19&3- 
 
 2. McCarthy, J. , "A Formal Description of a Subset of ALGOL", 
 
 In Steel, T. B. (editor), "Formal Language Description 
 Languages For Computer Programming", pp. 1-12, North 
 Holland, 1966. 
 
 3. McCarthy, J. and Painter, J. , "Correctness of a Compiler 
 
 For Arithmetic Expressions", in "Mathematical Aspects 
 of Computer Science", Proc. Symposia in Applied Math., 
 Vol. 19, pp. 33-41, American Math Society, 1967. 
 
 k. Bandat, K. , "On The Formal Definition of PL/l", Proc. AFIPS 
 1968 Spring Joint Computer Conference, Atlantic City, 
 New Jersey, pp. 363-373, April 1968. 
 
 5. Sidlo, John R. , "The List Processing Language NUCLEOL", Master 
 of Science dissertation, University of Illinois, Department 
 of Computer Science, Urbana, Illinois, August 1968. 
 
^ 
 
 6 
 
 \tf* 
 

,s* v 
 
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