herbie

You can click "derivation" to see the exact process it was derived. It's the first term of a taylor series expansion around x = 0, which is indeed f(0) = 1/sqrt(9*0-6) = sqrt(-1/6). I'm not sure why x was chosen outside of its input domain though. ---- ADDED LATER: I think I have the answer. Herbie seems to always assume x = 0, but there are a fixed set of transformations to get around that fact. Currently it only tries f(x), 1/f(x) and 1/-f(x) [1]. [1] https://github.com/herbie-fp/herbie/blob/b4a4bb4c61749912a64... > Maybe there aren’t any value options that provide a speedup, but the tool allows increasingly reduced accuracy (down to zero) until it finds a speedup? AFAIK Herbie works by trying a bunch of transformations to get candidate expressions and evaluate them to get the pareto frontier. So if there is a single constant expression

I found this: https://github.com/uwplse/herbie

This[1] looks like the GitHub account. So at least there's a readme. Here[2] is the Google Cache of the page. [1] https://github.com/uwplse/herbie [2] http://webcache.googleusercontent.com/search?q=cache:http://...