Back in the earlier days of AI, not that early, but the late 80's I was the lead developer for an AI research program being jointly conducted by 3 business professors from MIT, Harvard, and Boston University. We were working on "frame based knowledge representation" - frame of reference based node links between nodes containing something: a number, a word, a sentence, or a "function that combines linked nodes into a new frame of reference".

Long story short, we thought we were making a new type of N-dimensional spreadsheet, but after 3 semesters of work one of the advisors at MIT told us we need to meet his colleague, and that guy informed us we had a working compiler for a hybrid of Lisp and C.