[1] Olivier Danvy, "In Memoriam Peter Landin," *Vimeo*.

[2] His colleague Richard Bornat notes in a commemorative article in the *Formal Aspects of Computing* journal, that "It was at one of his dinner parties that those who reinvigorated Gay Pride marches in the mid 80s met, just in time for the battle over clause 28" Richard Bornat, "Peter Landin: a computer scientist who inspired a generation, 5th June 1930 - 3rd June 2009," *Formal Aspects of Computing* (2009) 21: 394.

[3] The two met at a party in which Gandy was arguing in support of the Communist line in the Winter War between the Soviet Union and Finland. For many years Gandy was a member of the Communist Party, yet somehow escaped scrutiny even after the controversy surrounding the Cambridge Five, the group of Soviet spies believed to have been recruited through the Apostles society at Cambridge.

[4] Gandy was a mathematician and logician, but not technically a computer scientist. In this sense he does not neatly fit into this history, but as one of Alan's closest friends he was the strongest link to his life and work until his death in 1995. Moreover, while Gandy's work in mathematical logic was not explicitly in the field of computing, it should be clear by now that the fields share a common history and are very much aligned.

[5] *Principia Mathematica*, mentioned previously with regards to Turing, is a three-volume set of texts written by Alfred North Whitehead and Bertrand Russell, published in 1910, 1912, and 1913 respectively. It is an attempt to derive all mathematical truths from a well-defined set of axioms and inference rules in symbolic logic. It is widely considered to be one of the most important and seminal works in mathematical logic and philosophy.

[7] Donald MacKenzie, *Mechanizing Proof: Computing, Risk, and Trust,* (Cambridge: MIT Press, 2004), 273.

[8] Rod Burstall, "Christopher Strachey – Understanding Programming Languages," *Higher Order and Symbolic Computation* 13 (2000), 51.

[10] C. Strachey, Curriculum Vitae (1971), Strachey Papers, A3.

[11] Landin, P. J. 1964. "The mechanical evaluation of expressions." *Computer J. 6*, 4, 308-320.

[13] The phrase "syntactic sugar" was also coined by Landin in 1964 to describe the surface syntax of A Programming Language (APL) which was defined semantically in terms of the applicative expressions of lambda calculus. It has come to refer to any syntax within a programming language that is designed to make things easier to read or to express, that is, it makes things "sweeter" for humans to use, even if they might be expressed more cleanly or succinctly in a number of alternate styles.

[14] The phrase "The Next 700…" has since been adopted as a kind of meme among computer scientists, spawning a number of speculative papers charting the future of a given field.

[15] Landin had previously been arrested while on a demonstration with the Committee of 100, the 1960s anti-war group founded by Bertrand Russell. He was sentenced Pentonville Prison, but only lasted a week before he became so bored that he paid the fine to be released. (via)

[16] In writing this piece I reached out to one of Peter Landin's children, but did not receive a response.

[18] In fact, Peter Landin never learned how to drive. He was well known for biking everywhere he went, even into his old age.

Comments