Tests are now using TrachtenbergResult, but this type is not defined in Preloaded, and the initial code is not updated to use it (the return type is still [(Int, String)]).

A description should be self-contained, and examples should not contain necessary specifications ( ie, the description should still be complete when skipping the examples ). The current description is thus missing a specification section for the Trachtenberg method; being able to reverse engineer it from the example is insufficient.

Apart from that, I sincerely doubt multiplying by two is interesting in itself, or by the Trachtenberg method, seeing how doing it by that method really doesn't add anything to the way I'd normally do it in my head ( and I'd never heard of this method before ). Maybe showcase the method better ( cq actually showcase it ) with a more complicated multiplication?