Remove the word "skolem" from user error messages
Skolem variables are not, as best I can tell, part of the type system; they are part of the implementation of the type checking algorithm. As such, it seems inappropriate to mention them in error messages. Instead, the error messages should explain things at the Haskell level.
Couldn't match expected type ‘t’ with actual type ‘a’ because type variable ‘a’ would escape its scope This (rigid, skolem) type variable is bound by...
I'd much rather see an explanation using words like "existentially quantified" and "right-hand side of a pattern match".
|Component||Compiler (Type checker)|