page 551, paragraph 5 : I have found the explanation of dig
and passing the remainder of the arguments to that result
a little bit short and unclear, I had to look at the documentation which has a link to Dig Methods.
In How Does dig Work? there is a nice explanation :
Each successive receiver is the value returned by the previous call to dig.
The explanation of Array#dig on page 532 was clear (with a small modification, see next post), so I suggest the following :
Hashes also respond to Hash#dig(key, *more_keys) by looking up the first argument in the hash and sending to that result the message dig with the remainder of the arguments.