The question that I'm curious about is "why does POSIX require unary negation to have a higher precedence?" Was it a "this is the way that bc worked in the 70s

The question that I'm curious about is "why does POSIX require unary negation to have a higher precedence?" Was it a "this is the way that bc worked in the 70s because it was easier to write a parser for it?" or was there some more underlying reason for the "this problem gets really icky if unary negation has lower precedence than the binary operators and makes for other expressions that become less reasonable?" It's like the Logical XOR issue ( https://youtu.be/4PaWFYm0kEw?t=2236&si=Wi0gwV-XctLGN98I https://youtu.be/4PaWFYm0kEw?t=2236&si=Wi0gwV-XctLGN98I ) ... and I'm of the opinion that there's a real reason why this design choice was made. (Aside: Some other historical "why things work that way" touching on dc's place in history: Ken Thompson interviewed by Brian Kernighan at VCF East 2019 https://youtu.be/EY6q5dv_B-o?si=YKr4j_FAEp-OihiX&t=1784 https://youtu.be/EY6q5dv_B-o?si=YKr4j_FAEp-OihiX&t=1784 - it goes on to pipes and dc makes an appearance there again)