I still don't understand the problem domain and solution space well enough. Your tests only prove that the feature works as you claim it works. We have no idea what an "alias"-heavy codecase looks like, how the feature interacts with the rest of Nim, what the gotchas might be, what the theory behind "alias" is, how it affects the compiler's error messages and -- most importantly -- whether there are alternatives. Maybe we can simply tweak the existing language to give us some/all of alias's benefits. And if we only get "some" of its benefits, maybe the other "benefits" aren't real, but gotchas.
Your "alias" design is biased: All it cares for is that examples A, B, C then "compile and work", but we also need to ensure that stuff that _shouldn 't_ compile does not suddenly compile...
