*Walter M. Carlson*

Page 395

A facility to permit conversationally controlled tasks to be executed in a noninteractive environment is proposed. A means by which programs can generate interactive time-sharing commands and receive the corresponding output
…

*Charles A. Grant*

Pages 403-406

LAP6 is an on-line system running on a 2048-word LINC which provides full facilities for text editing, automatic filing and file maintenance, and program preparation and assembly. It focuses on the preparation and editing of
…

*Mary Allen Wilkes*

Pages 407-414

STAGE2 is the second level of a bootstrap sequence which is easily implemented on any computer. It is a flexible, powerful macro processor designed specifically as a tool for constructing machine-independent software. In this …

*W. M. Waite*

Pages 415-421

In this paper trade-offs among certain computational factors in hash coding are analyzed. The paradigm problem considered is that of testing a series of messages one-by-one for membership in a given set of messages. Two new hash …

*Burton H. Bloom*

Pages 422-426

A general method of file structuring is proposed which uses a hashing function to define tree structure. Two types of such trees are examined, and their relation to trees studied in the past is explained. Results for the probability …

*E. G. Coffman, J. Eve*

Pages 427-432

A new version of the Euclidean algorithm for finding the greatest common divisor of

n integers

ai and multipliers

xi such that gcd =

x1 a1 + ··· +

xn an is presented. The number of arithmetic operations and the number of storage …

*Gordon H. Bradley*

Pages 433-436

This paper presents a canonical form for context-sensitive derivations and a parsing algorithm which finds each context-sensitive analysis once and only once. The amount of memory required by the algorithm is essentially no more …

*William A. Woods*

Pages 437-445

*Kathleen A. Paciorek*

Pages 446-447

*Gordon H. Bradley*

Pages 447-448

*Thomas Bray*

Page 448

*Edward W. Ng*

Pages 448-449

*Arthur H. J. Sale*

Page 449

We have read with much interest the paper “Automatic Segmentation of Cyclic Program Structures Based on Connectivity and Processor Timing” by T. C. Lowe [

Comm. ACM 13, 1 (Jan. 1970), 3-6, 9], and we congratulate the author on …

*Kirk Sattley, Robert Millstein*

Page 450

In “Synchronization in a Parallel-Accessed Data Base” [

Comm. ACM 12, 11 (Nov. 1969), 604-607] A. Shoshani and A. J. Bernstein have given a very lucid synthesis of diverse techniques to assure the integrity of a data base. But …

*H. D. Baecker*

Page 451

In [1] the authors use a lemma to prove their Theorem 1 (pp. 352-353). While the lemma is true, there is a defect in its proof, for one cannot assume that each of the symbols appearing as a type IV reference is in

t(

Ek ,

s).

k …

*John E. Pomeranz*

Page 451

Reference is made to the paper by C. A. R. Hoare [1] which discusses the fundamentals of an axiomatic approach to computer programming. One advantage for an axiomatic system proposed by Hoare is that an axiomatic description
…

*B. R. Hunt*

Page 452