Ah, also I should note that using braces for exponents in l3fp is wrong. It turns out to work incidentally, because these specific braces are basically ignored, so you get (1+1/1010)^1010. On 7/10/14, Bruno Le Floch <[log in to unmask]> wrote: > Hello Andrew, > > Very clearly a bug. Comes from a bug in the log function (well, the > more precise internal version that is used when computing powers) in > the range [1.00099009, 1.0009901) it seems, and probably some other > ranges. I'll investigate. > > Also, I'll likely answer at some point in the next couple of days to > your juxtaposition email. Sorry for the delay. > > Regards, > Bruno > > On 6/18/14, aparsloe <[log in to unmask]> wrote: >> \fp_eval:n { exp(1) - (1+1/1009)^{1009} } -> 0.001346 >> \fp_eval:n { exp(1) - (1+1/1010)^{1010} } -> 0.001613 >> \fp_eval:n { exp(1) - (1+1/1011)^{1011} } -> 0.001343 >