Here is an updated issues list:
1) R6RS provides define-enumeration to help set up enum-types. Is
this worth having? Possible syntax is: (define-enumeration <type-name>
(<symbol> ...) <constructor>)
This would bind <type-name> to the enum-type, and constructor to a
curried version of make-enum-set that already knows what type to use.
2) Should there be a mechanism to convert between integer sets and
integers as bitvectors, as defined in SRFI 33, SRFI 60, and R6RS?
6) Are bags really useful enough to include?
7) Should bags be called multisets (msets?) instead?
8) Should we switch to unique enum objects rather than symbols?
9) The word "set" is heavily overloaded. Should we use "gset" or