In 1965 Christopher Strachey introduced his termination problem, which I also call Strachey's Halting Problem in my writings, to the readership of The Computer Journal. Specifically, Strachey provided a “proof” that it is

impossible to write a program which can examine any other program and tell, in every case, if it will terminate or get into a closed loop when it is run. [5]

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?

Something significant happened during the 1950s in the history of science & technology. By 1950, logicians and linguists had been studying “artificial languages” and “natural languages” for centuries. But, the words “programming language” were not used at all. By 1959, however, those words had become common currency. And, in today's digital world, the absence of “programming languages” is totally unthinkable.

Dijkstra generalized his multiprogramming problem by seeking symmetries, as I've explained in a previous post. Below, I examine how Dijkstra also drew an analogy with hotel management to further simplify his multiprogramming concerns (EWD 54).