Gauss–Codazzi equations
In this context , the first equation , often called the Gauss equation ( after its discoverer Carl Friedrich Gauss ) , says that the Gauss curvature of the surface , at any given point , is dictated by the derivatives of the Gauss map at that point , as encoded by the second fundamental form . 
<triplet> Gauss curvature <subj> Carl Friedrich Gauss <obj> named after