it says "Finally, take that sum and divide it by 10. If the remainder equals zero, the original credit card number is valid", so it's explaining what modulus does, but in the code he puts the actually term modulus there to make it easier for us :)

In point 4, says "Divide by 10", while code example clearly states to use modulus. These are not the same.

Arguments (Haskell)

First argument: space-delimited list of minor words that must always be lowercase except for the first word in the string.

This description is hard-to-comprehend, I'd propose a change to: "space-delimited list of minor words that must always be lowercase, except if they appear as word in the string.". Otherwise, it is kind of implied that the first ford in teh list-of-exceptions is supposed to be capitalized or something.

See below. The current Haskell tests are botched, sorry. I'll file an issue on GitHub.

The instructions say "smaller" and "larger" will be the only words I need to handle, so why is my code passed ""smaller""? How does tat make sense as a test?