> Often in the MIT technical reports, one would see 'x = fu(y)' or 'y > bar(z)'

Hmm, "fu"? The decades confound my memory, but I don't immediately recall seeing a "fu" there? Before the "foo" of AIM-127a[1] in 1967 and MIT-LCS-TR-032[2] in 1966, there's still a decade of AI Memos, and couple of years of TRs. DSpace finds at least some "fu"s... lots of ocr fragments. The AITR-220 '64 hit is ocr fragment. My search-fu tonight wasn't up to being exhaustive (spot checks were all fragments). And also, OCR could be missing older "fu"s. But I didn't quickly find a real "fu".

A foo-bar-baz-quux in MIT-LCS-TR-365[3] in 1986.

One can start on the CSAIL collections page[4] and explore.

[1] "FOO" in abstract of AIM-127a LISP Linkage Feature: Incorporating MIDAS into PDP-6 LISP https://dspace.mit.edu/handle/1721.1/6136 [2] "Thus if FOO has the definition (LAMBDA (X Y) [alpha]), and the user calls SYSTEM1 with NAME= FOO, ADVICE= [beta], WHERE= BEFORE" on page 43 of MIT-LCS-TR-032 Pilot: A Step Towards Man-Computer Symbiosis https://dspace.mit.edu/handle/1721.1/149354 [3] "if the back trace is: FOO [1] <- BAR (2] <- BAZ [3] <- QUUX [4]" on page 20 of ID World: An Environment for the Development of a Dataflow Programs Written in ID MIT-LCS-TR-365 https://dspace.mit.edu/handle/1721.1/149633 [4] https://dspace.mit.edu/handle/1721.1/5458