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]

Dijkstra tackled the problem of allowing multiple users share the university's X8 computer and its peripheral hardware devices (EWD 51). To solve this problem, Dijkstra first reformulated it in terms of as many symmetries as he could find, thereby obtaining a more general problem description.

In early 1962, Edsger W. Dijkstra presented an analogy of a classroom teacher calling upon one of her pupils. By doing so, he conveyed some subtleties of “dynamic memory management” and “concurrent process behavior”.

Toward the end of my paper `Dijkstra's Rallying Cry for Generalization ...' I briefly describe the work of Irons and Feurzeig. These two men had by 1960 also implemented ALGOL60's recursive procedure just like Dijkstra and Zonneveld. Their solution, however, was very different from the solution proposed by Dijkstra and Zonneveld.

In his technical report (MR 34) of October 1961, Dijkstra made an analogy between human communication and communication with a machine and noted that the analogy is ineffective, an observation which complies with the earlier analogy he made between mathematics and programming, which he viewed to be effective.