Why do the read functions say they take in type `BN`?

[Surien Das-Giwojno]

Example:
When I try to do redSub(b: BN): RedBN it with a regular BN for b it gives me an error that says Error: red works only with red numbers.

So shouldn't the input type here be RedBN not BN?

[Kirill Fomichev]

Is this from some TS definition? If so, please contact the author of these definitions because we do not provide them.