I am using SRFI-225 for a library I am writing and had some questions
while trying to write an implementation of SRFI-225:

1. Do the generic procedures or the implementations in the DTO handle
optional arguments? The sample implementation of SRFI-225 handles
default arguments in generic procedures, but the SRFI doesn't specify
this behavior.

2. What are the default values for the arguments in procedures where the
arguments are optional? In the sample implementation, `dict-for-each`
and `dict->generator` use `#f` as the default arguments for `start` and
`end`.

3. What is the behavior of `dict-for-each` and `dict-generator` when the
underlying dictionary is not ordered when the procedure is given a start
or end argument?

4. The description of `dict-map` contains a typo. It should say

    > Returns a dictionary similar to dict that maps each [key] of dict
    > to the result of applying proc to the key and corresponding value
    > of dict.

5. `dict-remove` is listed as required in the SRFI text, but is also
listed as implemented in terms of the other procedures. It has a default
implementation in the reference implementation.

-- Peter McGoron