Interesting you should mention that, as today I just watched Gerald Jay Sussman&#x27;s NYCLisp talk, in which he discusses it starting at 29:00.<p><a href="https:&#x2F;&#x2F;vimeo.com&#x2F;151465912" rel="nofollow">https:&#x2F;&#x2F;vimeo.com&#x2F;151465912</a>