Is the history of computer science solely a history of progress? I don't think so. Judge for yourself by reading the present post in which I scrutinize the famous textbooks of John E. Hopcroft and Jeffrey D. Ullman.

Quotes from 1969 and 2007

I start by comparing the following two quotes. The first quote comes from Hopcroft & Ullman, 1969:

During the past seven years there have been only a handful of popularized books on engineering & science that I have read from cover to cover in less than a week. These books are listed here:

One of the questions that keeps me awake (during the day) is the following one:

What did a “computer program” mean to Actor X in 1973?

For example, both Christopher Strachey and Edsger Dijkstra viewed a “computer program” as a mathematical object, albeit of a very different kind [1]. (A decade or more earlier, both men did not associate computer programs with mathematical objects pur sang). But what about large parts of the North American computer industry in 1973? How did actors in this field view a “computer program” in 1973?

A recurring theme in my blog posts is the appropriation of the term “computer program” by Dijkstra and other researchers. The “computer program” concept has acquired at least four different meanings during the course of history. It can refer to: