A University of Twente mathematician's own eyewitness account confirms meeting Song Jian at the 1978 IFAC congress in Helsinki

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Geert Jan Olsder — a mathematician in the University of Twente's Systems and Control Theory department in the 1970s, later a TU Delft professor — is quoted directly by U-Today (the University of Twente's own journalism platform) confirming he personally met Song Jian at IFAC congresses: "At conferences of the International Federation of Automatic Control (IFAC), Olsder met the rocket scientist several times. 'In 1978 in Helsinki, but also six years later in Budapest.'" This is non-Greenhalgh eyewitness testimony that Song Jian was physically present at the 7th IFAC World Congress in Helsinki in 1978 — the same specific congress named in Greenhalgh's account and confirmed institutionally in claim-ifac-institutional-record-confirms-1978-helsinki-world-congress. It converges with, and is independent of, Dylan King's 2022 Palladium essay, which names the same congress via a different research thread.

Neither Olsder nor the Palladium essay quotes or names Liang Zhongtang's Chinese text describing an unnamed "academic visit to Europe" — so this is triangulation across separate accounts converging on the same date and city, not a single document that closes the identification outright. One limit on how independent the Olsder leg is: the same article dates his awareness of Greenhalgh's book to 2008, when a Trouw journalist approached him about being named in it, sixteen years before this 2024 interview. The bare recollection of meeting Song at IFAC congresses is his own and predates that contact; the significance he attaches to it does not, and a memory recalled inside a narrative one already knows is not gathered blind. That open question is tracked at question-song-jian-1978-europe-trip-identify-as-ifac-helsinki-congress. See also claim-olsder-account-traces-song-jian-twente-contact-to-1975-delegation-visit for a complication this same source introduces.