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Discusses the use of decision tables in solving large scale programming problems. Construction of an application program through the selection of certain source statements from a predefined file; Ideas behind the other historical approaches of solving programming problems.

Linguistic mechanisms which can be used to protect one subprogram from another's malfunctioning are described. Function-producing functions and various type-tagging schemes are considered. An attempt is made to distinguish between access limitation and authentication. [ABSTRACT FROM AUTHOR]

Most current programming languages treat computation over different classes of objects (e.g. numbers, strings, labels and functions). For correct compilation and execution, the following question then arises: is a program properly constructed so that its operations and operands are compatible? The activity of answering this question is usually called type checking. This paper attempts to isolate the notion of type checking and presents a partial solution to the type checking problem based on the notions of abstraction and application of functions. In particular, a program is mapped into an expression within a decideable subset of the λ-calculus, which characterizes the type relations within the program and eliminates all other information The determination of the type-wise correctness or incorrectness of the program is resolved by reducing its corresponding λ-calculus expression to one of two normal forms, the constant "correct" for a type-wise correct program or the constant "error." An application to type checking in Algol 60 is made, and the attendant problems faced for any notion of type checking are discussed. [ABSTRACT FROM AUTHOR]

The constructs of a simple programming language are introduced and described informally in terms of values and side-effects. A translator is defined which translates the language into flowcharts for a simple machine. The action of the machine in executing a flowchart is defined. A proof is constructed that the effect of translating and executing any program can be expressed solely in terms of the value and side-effect of the program. During the course of constructing the proof, formal definitions of the concepts of value and side-effect are derived in order to make the proof rigorous. Correctness of the implementation involves checking that the definitions derived in the step above are an acceptable formalization of the informal description given in the first step. [ABSTRACT FROM AUTHOR]

A new datatype, called a block, has been implemented for SNOBOL4. A block is a three-dimensional aggregate of characters in the form of a right parallelepiped, best thought of as a three-dimensional extension to a string. (The third dimension is used for overstriking.) Blocks may he printed, concatenated in any of three dimensions, and merged on the basis of program-defined connection points. Some blocks adapt In size and shape to their environment. Blocks and their operations are mainly used for composing printable output. A variety of graphical problems (including flowcharting, bargraphs, logic diagrams, mathematical-equation formation, and text justification and preparation) have been programmed on a printer in what appears to be an easy and natural way. In addition to these somewhat specialized applications, blocks appear to be a good general purpose device-independent output formation mechanism especially suitable for nonnumerical work. The concept of a block is largely language independent. That is, blocks require little in the way of specialized syntax and could readily be absorbed into the external structure of most programming languages. [ABSTRACT FROM AUTHOR]

Presents a notation for describing the semantics of data structures. Implementation facility which could be a part of a programming language; Expression of the semantics of an algorithm; Efficiency of the structures.

A proof is given of the correctness of the algorithm "Find." First, an informal description is given of the purpose of the program and the method used. A systematic technique is described for constucting the program proof during the process of coding it, in such a way as to prevent the intrusion of logical errors. The proof of termination is treated as a separate exercise. Finally, some conclusions relating to general programming methodology are drawn. [ABSTRACT FROM AUTHOR]

A method of analyzing statements in a programming language which can tolerate a considerable inaccuracy in their specification is proposed. This method involves principles at present mainly confined to studies in the area of artificial intelligence such as feature extraction, approximate tree matching, and strategy improvement by feedback from the matching process. A pilot program incorporating the principles is described and preliminary operating results are presented. A final section surveys further principles which are currently being investigated. [ABSTRACT FROM AUTHOR]

This paper discusses the multiplication of conformable sequences of row vectors, column vectors, and square matrices. The minimum time required to evaluate such products on ordinary serial computers as well as parallel computers is discussed. Algorithms are presented which properly parse suck matrix sequences subject to the constraints of the machine organization. [ABSTRACT FROM AUTHOR]

The paper describes a scheme for symbolic manipulation of index expressions which arise as a by-product of the symbolic manipulation of expressions in the matrix calculi described by the authors in a previous paper. This scheme attempts program optimization by transforming the original algorithm rather than the machine code. The goal is to automatically generate code for handling the tedious address calculations necessitated by complicated data structures. The paper is therefore preoccupied with "indexing by position." The relationship of "indexing by name" and "indexing by position" is discussed. [ABSTRACT FROM AUTHOR]

An elementary outline of the theorem-proving approach to automatic program synthesis Is given, without dwelling on technical details. The method Is Illustrated by the automatic construction of both recursive and Iterative programs operating on natural numbers, lists, ant frees. In order to construct a program satisfying certain specifications, a theorem induced by those specifications is proved, and the desired program Is extracted from the proof. The same technique is applied to transform recursively defined functions into iterative programs, frequently with a major gain in efficiency. It is emphasized that hi order to construct a program with loops or with recursion, the principle of mathematical Induction must be applied. The relation between the version of the induction rule used and the form of the program constructed is explored in some detail. [ABSTRACT FROM AUTHOR]