I recently stumbled on the following bug in the l3fp package: \fp_eval:n { sin( 2pi - .0001 ) } ==> 9999.999000000002 which seems a little excessive for a function bounded by +1, -1. \fp_eval:n { sin( 2pi - .001 ) } seems to evaluate correctly. The value between .001 and .0001 where the bug arises is between .001853071795, which is too small and brings on the error, and .001853071796, which doesn't. \fp_eval:n { sin( 2pi + .0001 ) } seems to evaluate correctly. However, the buggy behaviour repeats at 4pi and 6pi and presumably at any positive even multiple of pi, but not at 0 (= 0pi). For negative even multiples, \fp_eval:n { sin( -2pi - .0001 ) } seems to evaluate correctly but \fp_eval:n { sin(-2pi + .0001) } ==> -9999.999000000002 This aside, I greatly appreciate the facilities that the l3fp package provides. Andrew P.S. Is this a *very* quiet list, or have I not configured things correctly so that I'm missing postings to it?