I have an education in compsci, and I have worked in software engineering and platform engineering for 8 years now… And I only know of one programming language that makes use of “=/=” which is Erlang. Every other language or scientific papers I know of make use different operators.
Prolog comes close with “==”, and Haskell too with “/=”, but every other language has either used “!=”, “~=” or “<>”. The papers I have read that go for a more pseudo-code or mathematical notation has always used “≠”.
Upper lip or lower lip?