Stichting Mathematisch Centrum· 2E Boerhaavestraat 49 Amsterdam

Total Page:16

File Type:pdf, Size:1020Kb

Stichting Mathematisch Centrum· 2E Boerhaavestraat 49 Amsterdam zw stichting mathematisch ~ centrum· MC AFDELING ZUIVERE WISKUNDE zw 44/75 JUNE T .M. V. JANSSEN tN ARITHMETIZATION OF VAN WIJNGAARDEN GRAMMAR 7 L 2e boerhaavestraat 49 amsterdam Bl81.10l'~fi!il:{, MATHtMATISCH Cl'Nll/\•i.',li, PJu..n.:ted a..t the Ma..thema.:Uc..a.l Cen:tlie, 49, 2e BoeJihaave1:i.:tJr.aa.t, Am.o.teJidam. The Ma..thema:tic..a.l Cen:tlie, 6ou.n.ded .the 11-.th 06 FebJr..uafl_Y 1946, -loan.on.­ p1r..06U in..o.tltu.tlon. curn,ln.g a..t .the ph..omotion. 06 pUll.e ma..thema.:UCA an.d w app..Uc.a.:Uon..6. I.t -lo .opon..ooJr..ed by .the Nethe.Jilan.d6 GoveJin.men.:t .thh..ough the Nethe.Jilan.d6 01r..gan.,Lza.:Uon. 6oJr.. .the Advanc.emen.:t 06 PWl.e Re1:,ea1r..c.h (Z.W.O), by .the Mun.,Lupa..uty 06 Am.oteJidam, by .the Un.,lveMUy 06 Am.oteJidam, by the F1r..ee UniveMUy a..t Am.oteJidam, an.d by indU.6.:tluel:i. AMS(MOS) subject classification scheme (1970): 68A30, 02F43, 02F99 An Arithmetization of van Wijngaarden Grammar by T.M.V. Janssen ABSTRACT An arithmetization is given of the concept of a van Wijngaarden grannnar, by means of which it is proved that each van Wijngaarden grammar generates a recursively enumerable language. KEYWORDS & PHRASES: van Wijngaarden grarronar, arithmetization, generative aapaaity, reaursively enwnerable languages. INTRODUCTION Every recursively enumerable language can be generated by a van Wijngaarden grammar. This has been proved by SINTZOFF [9]; an elegant proof has been given by VAN WIJNGAARDEN [12] who showed that only one metanotion is needed to do so. The present report contains a formal proof of the reverse that each van Wijngaarden grammar generates a recursively enumerable language; no such proof has yet been given, as this fact is belied to be obvious by Church's thesis. The method of our proof is sketched as follows. A van Wijngaarden grammar concerns strings of symbols; it generates strings of special symbols and it gives rise to relations between strings (such as string s 1 can be obtained from string s 2 by applying some rule of the grammar). The problem we consider, is the question whether a set of special strings is recursively enumerable. We shall, however, not directly deal with this problem, but rather with a translation of it. We use a 1-1 encoding of strings of symbols in numbers. Relations between strings, become relations between numbers, and the problem becomes the question whether a set of special numbers is recursively enumerable. By solving the translated problem we have indirectly solved the original problem since the encoding is 1-1. This method, which is called arithmetization, is well known in recursion theory. We actually will obtain the result by defining a predicate wordgener­ ation (X,w,d), where Xis the code number of a van Wijngaarden grammar, w is the code number of a string and d encodes all the information about the derivation of w. From the definition of this predicate it will become clear that this predicate is primitive recursive. Apparently w E L(X) iff 3d[wordgeneration(X,w,d)], thus L(X) is recursively enumerable. The predi­ cate wordgeneration can actually be shown to be elementary recursive; this shows that the arithmetization is of the same complexity as the well known arithmetizations of Turing machines and of Markov algorithms. 2 FROM FORMAL LANGUAGE THEORY We recall the following from formal language theory; for details see HOPCROFT & ULLMAN [6]. Let V be a finite set. Then V+ is the set of all non empty strings consisting of elements from V, thus V+ = {v1···vn n ~ I, v. EV}. We indicate the empty string with A and put v* = V+ u {A}. 1. For w Ev*, let lwl denote the length of w. We designate a Chomsky grammar ( shortly grammar) by G = (V, E, P, S) where V is a finite set, E c V, SE V-E and Pc V+xv* is a finite set: the rules or productions. If there are no restrictions on P, then G is of Chomsky type O or shortly type-O. If Jul s lvl for each (u,v) E P then G is context-sensitive. If u E V-E for each (u,v) E P then G is context-free. If (u,v) E P and x,y Ev* then xuy Gxvy. We denote by i the transitive, reflexive closure of G" We omit subscripts G when no confusion is likely. The language gener­ ated by G is L(G) = {w Er* I S ! w}. A A-rule is a rule (u,v) E P with v = A. A homomorphism his a mapping v* • w*, where V and Ware finite sets, and h(xy) = h(x)h(y) for all x,y EV.* FROM RECURSION THEORY We recall the following facts from recursion theory; for details and proofs see DAVIS [3]. (I) The operation composition associates with the functions Ay 1 ••. ym f(y 1, ... ,ym), Ax 1 ••• xn g(x1, ••• ,xn), ••• , Ax 1 ... xn g(x1, •.• ,xn) the function (2) The operation of primitive recursion associates with the given total functions Ax 1 ••. xn f(x 1, ••• ,xn) and Azyx 1 ••• xn g(z,y,x1, ••• ,xn) the function Azx ••• x h(z,x , ••• ,x) where for all z,x , ••• ,x the 1 n 1 n I n following holds: 3 h(O,x1, ••• ,xn) = f(x1, ••• ,xn) , h(z+t,x1, ••• ,xn) = g(z,h(z,x1, ••• ,xn),x1, ••• ,xn). (3) A function is called a primitive reau:t'sive function if it can be obtained by a finite number of applications of the operations of composition and primitive recursion, beginning with functions from the following list: (i) >..x(x+l), (ii) >..x(O), (iii) >..x ••• x (x.). 1 n 1 (4) The following functions are primitive recursive >..xy(x+y) >..xy(xy) (5) Ann-place predicate Pis called a primitive recursive predicate if the characteristic function of the set {(x1, ••• ,xn) I P(x1, ••• ,xn)} is primitive recursive. (6) If P and Qare primitive recursive predicates, then so are the conjunc­ tion PA Q, the disjunction P v Q, the implication P • Q and the negated predicate 7 P. (7) The predicates<,~,>,~,=,* are primitive recursive. (8) If P(y,x1 , ••• ,xn) is a primitive recursive predicate, then the predicates R(zl ,zz,Xl ' ••• ,xn), meaning 3y[(z1 ~ y :;_ z2 A P(y,x1, ••• ,xn)J and S(z1 ,z2,x1 , ••• ,xn), meaning Vy[(z 1 ~ y ~ z2 • P(y,x1, ••• ,xn)J are again primitive recursive. The usual notation for these two predicates are Zz 3y P(y,x , ••• ,xn) zl 1 and z2 '/Y P(y,xt,···,xn) 1 respectively. 4 (9) We use the ~allowing definition of recursively enumerable set (this definition is equivalent to the one given by DAVIS [3]): A set Sis called recUPsiveZy enumerabZe if there exists a primitive recursive predicate P(x,y) such that S = {x I 3y P(x,y)}. CODING In the sequel we encode sequences of natural numbers in natural numbers; therefore, we need a primitive recursive function from nQO lNn to 1N. For convenience we require this function to be onto. The value of the function for the sequence x 1, .•• ,xn is denoted by tx1, .•. ,xn*· The value for the empty sequence is denoted by f *· We require this function to have the property that for all I$ i $ j $ n holds: f x. , ... , x . * $ t x , ... , x. , ..• , x . , ... , x * . l. J 1 i J n We require the following functions and predicate to be primitive recursive: the function L , which gives the length of an encoded sequence; thus L(fx1, •.. ,xn*) = n; the function( •• )., which gives the i-th element of a sequence; thus l. (tx , ••. ,x *>· = x. for I $ i $ n; 1 n l. l. the function* , which gives the code number of the concatenation of two sequences; thus X*Y = Hx)1,···,<x\(x),<Y)1,····(y\cy)*; the predicate EZem, where EZem(X,x) holds if£ for some i the i-th element in the sequence encoded by X, equals x. We define the primitive recursive function AXY • it(x,y) by { it(x,0) = t * it(x,n+I) = it(x,n) * Ox*). The primitive recursive function AX It(x) is now defined by It(x) = it(x,L(x)). The function It has the following useful! property. Let a= ta1, ..• ,an*' b = {b , ..• , b *• where m $ n, and let b , , •• and b be equal to subsequences of 1 m I m a , ... ,a (with b. = t * for at most one i). Then b $ It(a). We will use 1 n l. this estimate to bound quantifications. 5 There are several codings which have the desired properties and for which the required functions and predicate are primitive recursive. For example, see TROELSTRA [10] (proofs concerning the properties of this code are found in §:Z of KREISEL & TROELSTRA [7]) or VAN WIJNGAARDEN [13]. Tl1e actual choice of this code is, for our aims, arbitrarily. Even the use of an onto coding is not essential (for a code which is not onto see DAVIS [3]), but then one needs a primitive recursive predicate which tells whether a number is the code number of a sequence, and the definitions of the func­ tions and predicate have to be adjusted in order to remain total. DEFINITIONS CONCERNING VAN WIJNGAARDEN GRAMMARS A van Wijngaarden grammar (W-grammar) is an ordered sixtuple G = (VM,IT,L,PM,PH,S) where the following holds: VM is a finite set, the elements of which are called metavariahles; L is a finite set, the elements of which are called terminal symbols or terminals; IT is a finite set, the elements of which are called protovariables; S is a special symbol in IT, called the start symbol.
Recommended publications
  • Evidence and Counter-Evidence : Essays in Honour of Frederik
    Evidence and Counter-Evidence Studies in Slavic and General Linguistics Series Editors: Peter Houtzagers · Janneke Kalsbeek · Jos Schaeken Editorial Advisory Board: R. Alexander (Berkeley) · A.A. Barentsen (Amsterdam) B. Comrie (Leipzig) - B.M. Groen (Amsterdam) · W. Lehfeldt (Göttingen) G. Spieß (Cottbus) - R. Sprenger (Amsterdam) · W.R. Vermeer (Leiden) Amsterdam - New York, NY 2008 Studies in Slavic and General Linguistics, vol. 32 Evidence and Counter-Evidence Essays in honour of Frederik Kortlandt Volume 1: Balto-Slavic and Indo-European Linguistics edited by Alexander Lubotsky Jos Schaeken Jeroen Wiedenhof with the assistance of Rick Derksen and Sjoerd Siebinga Cover illustration: The Old Prussian Basel Epigram (1369) © The University of Basel. The paper on which this book is printed meets the requirements of “ISO 9706: 1994, Information and documentation - Paper for documents - Requirements for permanence”. ISBN: set (volume 1-2): 978-90-420-2469-4 ISBN: 978-90-420-2470-0 ©Editions Rodopi B.V., Amsterdam - New York, NY 2008 Printed in The Netherlands CONTENTS The editors PREFACE 1 LIST OF PUBLICATIONS BY FREDERIK KORTLANDT 3 ɽˏ˫˜ˈ˧ ɿˈ˫ː˧ˮˬː˧ ʡ ʤʡʢʡʤʦɿʄʔʦʊʝʸʟʡʞ ʔʒʩʱʊʟʔʔ ʡʅʣɿʟʔʱʔʦʊʝʸʟʷʮ ʄʣʊʞʊʟʟʷʮ ʤʡʻʒʡʄ ʤʝɿʄʼʟʤʘʔʮ ʼʒʷʘʡʄ 23 Robert S.P. Beekes PALATALIZED CONSONANTS IN PRE-GREEK 45 Uwe Bläsing TALYSCHI RöZ ‘SPUR’ UND VERWANDTE: EIN BEITRAG ZUR IRANISCHEN WORTFORSCHUNG 57 Václav Blažek CELTIC ‘SMITH’ AND HIS COLLEAGUES 67 Johnny Cheung THE OSSETIC CASE SYSTEM REVISITED 87 Bardhyl Demiraj ALB. RRUSH, ON RAGUSA UND GR. ͽΚ̨ 107 Rick Derksen QUANTITY PATTERNS IN THE UPPER SORBIAN NOUN 121 George E. Dunkel LUVIAN -TAR AND HOMERIC ̭ш ̸̫ 137 José L. García Ramón ERERBTES UND ERSATZKONTINUANTEN BEI DER REKON- STRUKTION VON INDOGERMANISCHEN KONSTRUKTIONS- MUSTERN: IDG.
    [Show full text]
  • International Standard ISO/IEC 14977
    ISO/IEC 14977 : 1996(E) Contents Page Foreword ................................................ iii Introduction .............................................. iv 1Scope:::::::::::::::::::::::::::::::::::::::::::::: 1 2 Normative references :::::::::::::::::::::::::::::::::: 1 3 Definitions :::::::::::::::::::::::::::::::::::::::::: 1 4 The form of each syntactic element of Extended BNF :::::::::: 1 4.1 General........................................... 2 4.2 Syntax............................................ 2 4.3 Syntax-rule........................................ 2 4.4 Definitions-list...................................... 2 4.5 Single-definition . 2 4.6 Syntactic-term...................................... 2 4.7 Syntacticexception.................................. 2 4.8 Syntactic-factor..................................... 2 4.9 Integer............................................ 2 4.10 Syntactic-primary.................................... 2 4.11 Optional-sequence................................... 3 4.12 Repeatedsequence................................... 3 4.13 Grouped sequence . 3 4.14 Meta-identifier...................................... 3 4.15 Meta-identifier-character............................... 3 4.16 Terminal-string...................................... 3 4.17 First-terminal-character................................ 3 4.18 Second-terminal-character . 3 4.19 Special-sequence.................................... 3 4.20 Special-sequence-character............................. 3 4.21 Empty-sequence....................................
    [Show full text]
  • 17191931.Pdf
    PDF hosted at the Radboud Repository of the Radboud University Nijmegen The following full text is a publisher's version. For additional information about this publication click this link. http://hdl.handle.net/2066/113622 Please be advised that this information was generated on 2017-12-06 and may be subject to change. Description and Analysis of Static Semantics by Fixed Point Equations Description and Analysis of Static Semantics by Fixed Point Equations Een wetenschappelijke proeve op het gebied van de Wiskunde en Natuurwetenschappen Proefschrift ter verkrijging van de graad van doctor aan Katholieke Universiteit te Nijmegen, volgens besluit van college van decanen in het openbaar te verdedigen maandag 3 april 1989, des namiddags te 1.30 uur precies door Matthias Paul Gerhard Moritz geboren op 13 mei 1951 te Potsdam-Babelsberg druk: Bloembergen Santee bv, Nijmegen Promotor: Prof. C.H.A. Koster ISBN 90-9002752-1 © 1989, M. Moritz, The Netherlands I am grateful to many present and former members of the Nijmegen Informatics Department for numerous constructive dis­ cussions and for their comments on earlier drafts of this thesis. Contents Contents 1 1 Introduction 5 1.1 A Personal View 6 1.2 Description and Implementation 9 1.2.1 Syntax of Programming Languages 10 1.2.2 Semantics of Programming Languages ... 11 1.2.3 Static Semantics of Programming Languages 12 1.3 Our Aim 13 1.4 Overview 14 1.5 Related Work 15 2 Posets and Lattices 19 2.1 Partially Ordered Sets 19 2.2 Functions on Partially Ordered Sets 24 2.3 Construction of Posets 25 2.4 Lattices 29 2.5 Construction of Complete Lattices 31 2.6 Reflexive Lattices 34 1 2 CONTENTS 2.7 Functions on Lattices 35 2.8 Fixed Points 38 3 Description of Systems by Graphs 41 3.1 Graphs and Systems 42 3.1.1 Graph Schemes 42 3.1.2 Graph Structures 44 3.2 Functions on Graphs .
    [Show full text]
  • The History of the ALGOL Effort
    Technische Universiteit Eindhoven Department of Mathematics and Computer Science The History of the ALGOL Effort by HT de Beer supervisors: C. Hemerik L.M.M. Royakkers Eindhoven, August 2006 Abstract This report studies the importancy of the ALGOL effort for computer science. Therefore the history of the ALGOL effort is told, starting with the compu- tational context of the 1950s when the ALGOL effort was initiated. Second, the development from IAL to ALGOL 60 and the role the BNF played in this development are discussed. Third, the translation of ALGOL 60 and the establishment of the scientific field of translator writing are treated. Finally, the period of ALGOL 60 maintenance and the subsequent period of creating a successor to ALGOL 60 are described. ii Preface This history on the ALGOL effort was written as a Master thesis in Com- puter Science and Engineering (Technische Informatica) at the Eindhoven University of Technology, the Netherlands. iii Contents Abstract ii Preface iii Contents iv 0 Introduction 1 0.0 On the sources used ........................ 2 0.1 My own perspective ........................ 3 0.2 The ALGOL effort: a definition .................. 4 0.3 Notes ................................ 4 1 Creation 5 1.0 The start of the ALGOL effort ................... 5 1.1 The need for a universal algorithmic language ........... 7 1.1.0 The American field of computing ............. 7 1.1.1 The European field of computing ............. 9 1.1.2 The difference between Europe and the USA and the need for universalism ...................... 11 1.2 Why was IAL chosen over other algorithmic languages? ..... 11 1.2.0 IT ............................
    [Show full text]
  • Van Wijngaarden Grammars, Metamorphism and K-Ary Malwares
    Van Wijngaarden grammars, metamorphism and K-ary malwares. Gueguen Geoffroy ESIEA Laval Laboratoire de cryptologie et de virologie opérationelles (C + V )O, 38 rue des Dr Calmette et Guérin 53000 Laval, France [email protected] October 28, 2018 Abstract recognizers of a language are known. Van Wijngaarden grammars are different than the one Grammars are used to describe sentences structure, which fall in Chomsky’s classification. Their writing thanks to some sets of rules, which depends on the is particular, and above all, their production process is grammar type. A classification of grammars has been quite different than the grammars in Chomsky’s hierar- made by Noam Chomsky, which led to four well-known chy. We will see that these grammars may be used as types. Yet, there are other types of grammars, which do “code translators”. They indeed have some rules which not exactly fit in Chomsky’s classification, such as the allow them to be very expressive. two-level grammars. As their name suggests it, the main idea behind these grammars is that they are composed of two grammars. 2 Metamorphism vs. Polymor- Van Wijngaarden grammars, particularly, are such phism grammars. They are interesting by their power (expres- siveness), which can be the same, under some hypothe- The difference between polymorphism and metamor- ses, as the most powerful grammars of Chomsky’s clas- phism is often not very clear in people’s mind, so we sification, i.e. Type 0 grammars. Another point of inter- describe it quickly in this section. est is their relative conciseness and readability.
    [Show full text]
  • Inductive Types in Constructive Languages
    UNIVERSITY OF GRONINGEN Inductive Types in Constructive Languages Peter J. de Bruin March 24, 1995 Abstract Logic grammar is used to partly define a formal mathematical language “ADAM”, that keeps close to informal mathematics and yet is reducible to a foundation of Constructive Type Theory (or Generalized Typed Lambda Calculus). This language is employed in making a study of inductive types and related subjects, as they appear in languages for constructive mathematics and lambda calculi. The naturality property of objects with type parameters is described and employed. Cover diagram Behold the mathematical universe, developing from original unity into categorical duality. The central beam contains the initial and the final type, together with the remaining flat finite types. It is flanked by the dual principles of generalized sum and product, and of initial and final fixed point construction. Printed by: Stichting Drukkerij C. Regenboog, Groningen. RIJKSUNIVERSITEIT GRONINGEN Inductive Types in Constructive Languages Proefschrift ter verkrijging van het doctoraat in de Wiskunde en Natuurwetenschappen aan de Rijksuniversiteit Groningen op gezag van de Rector Magnificus Dr. F. van der Woude in het openbaar te verdedigen op vrijdag 24 maart 1995 des namiddags te 4.00 uur door Peter Johan de Bruin geboren op 20 september 1964 te Harderwijk Promotor: Prof. dr. G. R. Renardel de Lavalette Preface The fascination for mathematical truth has been the driving force for my research as it had been for my master’s thesis written in Nijmegen. Being amazed at the lack of a general language for the irrefutable expression of mathematical argument, I looked for it in the direction of what is called Type Theory.
    [Show full text]
  • An Abstract of a Thesis Properties of Infinite
    AN ABSTRACT OF A THESIS PROPERTIES OF INFINITE LANGUAGES AND GRAMMARS Matthew Scott Estes Master of Science in Mathematics Traditionally, languages are described as infinite sets, in this thesis, methods for specifying infinite grammars are explored. The effects of an infinite grammar on the language specified are examined along with several proofs. The relationship between grammars and semantics to specify the behaviour of formal systems is also explored. PROPERTIES OF INFINITE LANGUAGES AND GRAMMARS A Thesis Presented to the Faculty of the Graduate School Tennessee Technological University by Matthew Scott Estes In Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE Mathematics May 2005 Copyright c Matthew Scott Estes, 2005 All rights reserved CERTIFICATE OF APPROVAL OF THESIS PROPERTIES OF INFINITE LANGUAGES AND GRAMMARS by Matthew Scott Estes Graduate Advisory Committee: Alex Shibakov, Chairperson date Jeff Norden date Allan Mills date Mike Rogers date Approved for the Faculty: Francis Otuonye Associate Vice-President for Research and Graduate Studies Date iii STATEMENT OF PERMISSION TO USE In presenting this thesis in partial fulfillment of the requirements for a Master of Science degree at Tennessee Technological University, I agree that the University Library shall make it available to borrowers under rules of the Library. Brief quota- tions from this thesis are allowable without special permission, provided that accurate acknowledgment of the source is made. Permission for extensive quotation from or reproduction of this thesis may be granted by my major professor when the proposed use of the material is for scholarly purposes. Any copying or use of the material in this thesis for financial gain shall not be allowed without my written permission.
    [Show full text]
  • Science, Mathematics, Computer Science, Software Engineering†
    © The Author 2011. Published by Oxford University Press on behalf of The British Computer Society. All rights reserved. For Permissions, please email: [email protected] Advance Access publication on 12 September 2011 doi:10.1093/comjnl/bxr090 Science, Mathematics, Computer Science, Software Engineering† Dick Hamlet∗ Department of Computer Science, Portland State University, Portland, OR 97207, USA ∗Corresponding author: [email protected] This paper examines three ideas: First, the traditional relationship between a science, the mathematics it uses and the engineering based on it. Second, the nature of (software) computer science, which Downloaded from may not be a science at all, and its unusual use of mathematics. And finally, the nature of software engineering, its relationship with computer science, and its use of mathematics called ‘formal methods’. These three ideas turn on the first of them, since the scientific world view seems natural for the study of computing. The paper’s thesis is that while software touches science in many ways, it does not itself have a significant scientific component. For understanding programming, for teaching it and for applying it in the world, science is the wrong model. Mathematics has found its own foundations http://comjnl.oxfordjournals.org/ apart from science, and computer science must do the same. Keywords: science; engineering; philosophy; computing Received 28 April 2011; revised 11 August 2011 Handling editor: Mark Josephs at Portland State University on July 21, 2016 1. TRADITIONAL SCIENCE AND ENGINEERING engineering, where the Fourier and Laplace transforms are used (AND MATHEMATICS) to convert differential equations into algebra. Where a physicist understands an electronic circuit as a set of simultaneous In the well-ordered scientific world that began with Galileo differential equations, an electrical engineer can describe the and Newton, the disciplines of science, mathematics and circuit without calculus.2 engineering subdivide the intellectual space and support each other.
    [Show full text]
  • Iso/Iec Standard
    INTERNATIONAL ISO/IEC STANDARD First edition 1996-l 2-l 5 Information technology - Syntactic metalanguage - Extended BNF Technologies de /‘information - Mbtalangage syntaxique - BNF &endu Reference number ISO/IEC 14977:1996(E) ISO/IEC 14977 : 1996(E) Contents Page Foreword ............................................. Introduction ........................................... 1 Scope .............................................. 2 Normative references .................................. 3 Definitions .......................................... 4 The form of each syntactic element of Extended BNF .......... 4.1 General ......................................... 2 4.2 Syntax ......................................... 2 4.3 Syntax-rule ...................................... 2 4.4 Definitions-list .................................... 2 4.5 Single-definition ................................... 2 4.6 Syntactic-term .................................... 2 4.7 Syntactic exception ................................ 2 4.8 Syntactic-factor ................................... 2 4.9 Integer ......................................... 2 4.10 Syntactic-primary .................................. 2 4.11 Optional-sequence ................................. 3 4.12 Repeated sequence ................................. 3 4.13 Grouped sequence ................................. 3 4.14 Meta-identifier .................................... 3 4.15 Meta-identifier-character ............................. 3 4.16 Terminal-string. ................................... 3 4.17 First-terminal-character
    [Show full text]
  • On the Transformational Derivation of an Efficient Recognizer for Algol 68
    On the Transformational Derivation of an Efficient Recognizer for Algol 68 Caspar Derksen [email protected] August 1995 Masters Thesis no. 357 Catholic University of Nijmegen Preface This work is the result of my graduation project at the Catholic University of Nijmegen. It has been supervised by Prof. C.H.A. Koster. I should like to thank my parents, Donald, Cindy, Walter, Joyce, Berry, and others for their friendship and support while I was working on this thesis. Thanks go to Paula, Marco, Erik and others for enlightening life at the office during work. Special thanks go to Prof. C.H.A. Koster for awakening my interest in two level grammars and for his support and invaluable advice and patience. Caspar Derksen Nijmegen, August 1995 i ii Abstract During the sixties two level van Wijngaarden grammars (2vwg) were introduced for the formal definition of Algol 68. Two level van Wijngaarden grammars provide a formalism suited for writing rigorous formal definitions which read like human prose. Both the context free and context sensitive syntax of Algol 68 are defined in 2vwg. However, the specification is not executable. The Extended Affix Grammar (eag) formalism is closely related to 2vwg. Any 2vwg can be simulated in eag. From a given eag an exact recognizer for the language defined by the eag can be derived automatically. Termination of such a recognizer is guaranteed if certain liberal well-formedness conditions are satisfied. However, in general some effort is necessary to enforce well-formedness. cdl3 is a programming language which rides the borderline between affix grammars and programs.
    [Show full text]
  • University of Groningen Inductive Types in Constructive Languages Bruin, Peter Johan De
    University of Groningen Inductive types in constructive languages Bruin, Peter Johan de IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 1995 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Bruin, P. J. D. (1995). Inductive types in constructive languages. s.n. Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license. More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne- amendment. Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Download date: 29-09-2021 UNIVERSITY OF GRONINGEN Inductive Types in Constructive Languages Peter J. de Bruin March 24, 1995 Abstract Logic grammar is used to partly define a formal mathematical language “ADAM”, that keeps close to informal mathematics and yet is reducible to a foundation of Constructive Type Theory (or Generalized Typed Lambda Calculus).
    [Show full text]
  • Procedure Call and Return
    Chapter 11 Procedure Call and Return This chapter discusses the design of code fragments which support procedure call and return in both recursive and non-recursive programming languages. To aid the discussion in later chapters it includes a model of procedure call and return based on the notion of a procedure activation record. A procedure activation is a special case of a `micro-process',1 and the same model can explain the operation of languages such as SIMULA 67 whose control structures are not restricted to simple procedure call and return. It also helps to explain how restrictions on the use of data and procedures in the source language can allow restricted (and therefore less costly) implementations of the general procedure call and return mechanism. The mechanism of procedure call and return in FORTRAN is briefly discussed: then I concentrate on the mechanisms of stack handling which are required to implement procedure call and return in a recursive language on a conventional object machine. 11.1 The Tasks of Procedure Call and Return Fragments Each procedure body in the source program is represented by a section of in- structions in the object program. When a procedure has been called, and before it returns, various items of information represent the state of the current pro- cedure activation. The instruction pointer defines a position in the code, the contents of the data frame (see chapters 1 and 8) define the values both of the parameters and of any data objects owned by the activation, and an explicit or implicit collection of pointers defines the activation's environment { those non-local data frames which the current procedure activation may access.
    [Show full text]