The Little Prover and Scheme 48

Hello,

I tried using J-Bob in my favorite scheme implementation and
immediately ran into problems. Evaluating (atom '(ham eggs)) lead to a
Scheme48 heap overflow. When I typed in what I thought was the
troublesome definition myself nothing was wrong.

The relevant file is at
https://github.com/the-little-prover/j-bob/blob/master/scheme/j-bob-lang.scm.
I gave it a look, but didn't find anything that explained why Scheme48
behaved the way it did.

Sincerely,
Watson