This is more about the numeric tower, which common lisp does quite well, whilst JavaScript leans pretty heavily onto IEEE 754. (rev 2008 in the above linked spe

This is more about the numeric tower, which common lisp does quite well, whilst JavaScript leans pretty heavily onto IEEE 754. (rev 2008 in the above linked spec). And IEEE 754 has quite a number of edge cases that people find surprising, including things like operations only have to be reproducible up to a certain epsilon - an epsilon that is only defined to a minimum range in JavaScript.