Ref. SRFI 150 (Draft #2 published: 2017/8/8).

  - Very minor typos etc.:

    - In "Compatibility to the SRFI 99..." section:

      - 2nd item: "procedure" -> "procedural"

      - 3rd item: "of of" -> "of"

      - Last sentence: "unambiguously" -> "unambiguous"

  - Observations with a few implementations on the "deftuple" example,
    which is very nice.  (Nothing surprising; just for completeness.)

    - Chibi 0.8.0: gives specified results.

    - Larceny 1.3: accepts, but gives (2 2) instead of (1 2).

    - Chicken 4.9.0.1 (rather old; sorry): same as Larceny.

    - Kawa 3.0: rejects with error message: "duplicate declaration of 'tmp'"

    - Chez 9.4: rejects with error message "invalid define-record-type
      clause (make-tmp tmp tmp) ..."

Regards,

-chaw

P.S. I haven't yet tested the sample implementation but hope to do so
later today.