Hello Scott, I had mistakenly defined the internal \__fp_trap:nn and documented \fp_trap:nn. This should be fixed in a more recent version of the l3kernel bundle (and I updated the "added" date). Can you update to a version later than 2012/07/19? I'm very interested to have feedback on that function: this is very much experimental, and I am not yet sure how much I should implement of IEEE's trap mechanism. Sorry for the mistake. Bruno On 8/27/12, scott heard <[log in to unmask]> wrote: > Hello, I'm getting an undefined control sequence when trying to use this in > a > minimal document as "\fp_trap:nn {invalid_operation}{none}". > The documentation I have says that it was added on 2012-05-28 and the > version of > expl3 that I have is v3990, dated 2012/07/16. Is this an issue on my end? > scott >