That's not how it works when you create this kind of derivative.  The *whole* of the derivative work goes under the MIT license because it has to if it's going to be a SRFI.  That's a requirement of the publisher.

Then we say "Portions <Olin's copyright notice> under the following license" and subjoin the BSD license.  In order to comply with the BSD license, we have to preserve the copyright notice and the BSD license *as is* even though it is not the license we are using.  It is not our responsibility to say which portions we used.  Anyone who wants to make another derivative work can go to Olin's original themselves.

An analogy is Alice's movie made from Bob's book. The book has one copyright owner and one license, but as long as the movie complies with the license, the *whole* movie is under Alice's copyright, not Bob's.  Charlie can make his own movie if Bob's license allows him to, his movie is entirely under his copyright.  It is Charlie's responsibility not to reuse any of Alice's original content.

These rules don't normally apply to software because software is made of separate components, like an anthology of short stories, each with its own copyright.  The only copyright the anthology as a whole has is on the selection and ordering of stories. Any code taken from Chibi has to be under its copyright notice and license.

I am not a lawyer; this is not legal advice.  But it is not the unauthorized practice of law, either.

John Cowan          http://vrici.lojban.org/~cowan        xxxxxx@ccil.org
Original line from The Warrior's Apprentice by Lois McMaster Bujold:
"Only on Barrayar would pulling a loaded needler start a stampede toward one."
English-to-Russian-to-English mangling thereof: "Only on Barrayar you risk to
lose support instead of finding it when you threat with the charged weapon."