The ligature ≠ for != is very C/C++/Java-specific, which is kind of annoying. Is there a way to selectively disable ligatures like this one?
Having a ligature for != but not for the others betrays its language-independent semantics.
!= in Matlab is not legal logic operator.
Also, != might be part of regular expression.
Using Haskell is one such situation. Haskell's inequality operator is /= which someone could expect when they see ≠. Some people redefine != as a custom operator (see link), which can bring even more confusion with this ligatures.