Dijkstra attended the four-day “International Symposium on Algorithmic Languages” in honor of Aad van Wijngaarden who was retiring as director of Amsterdam's `Mathematical Centre'. The symposium was held from Monday 26 October until Thursday 29 October 1981. Ershov and Turski also attended after having spent the weekend with Dijkstra at his home in Nuenen.
Dijkstra had been Van Wijngaarden's PhD student during the 1950s. By the end of that decade, Van Wijngaarden had lost his wife in a car accident. As a result, he became estranged from many friends and colleagues in later years. During the 1960s and later, Van Wijngaarden and Dijkstra became more distanced from each other, as the following 1981 description by Dijkstra of the aforementioned event illustrates:
As a member of the Program Committee I knew that it would not be a very good conference; apparently the computing community had sensed this, for there were only about 125 participants. [...] The conference quite clearly suffered from the fact that it had been organised in honour of van Wijngaarden, who was sitting in the front row. A number of speakers really deserved to be torn apart, but the audience did not do it (or the chairman did not allow it) for fear of spoiling the fun for van Wijngaarden.
Equally noteworthy is that Dijkstra praised Naur's talk at the symposium even though, from Naur's point of view, their relationship had ceased to be friendly during the late 1960s and the early 1970s. Based on similar observations that I have made from other sources, I am currently inclined to ascertain that Dijkstra did not share Naur's animosity.
Some other speakers at the symposium were R. Schild, B. Meyer, M. Broy, M. Sato, and J.C. Reynolds. The rest of the talks were according to Dijkstra not very good. Darlington's talk in particular was “totally unconvincing” to Dijkstra. This was not the first time that Dijkstra expressed such reservations.
Source: EWD 805, written on 30 October 1981.