bit more and then some paper start coming out and then you realize of course locally it's very good locally you can write down any function so f theta is my neural network function it's essentially equal to some F 0 it's not important think of f 0 as 0 or very close to 0 some order one quantity a gradient term and a second order term so of course since I'm local the second order term should be thought of as smaller than the delayed the linear term so we kind of just throw it away and that's what these papers are doing and