Primal problem
= Primal problem
{title2=$\inf_x\varphi(x)$}
The original <mathematical optimization> problem relative to a chosen <Lagrangian dual problem>. In <convex perturbation duality>, its objective is $\varphi(x)=f(x,0)$ and its value is $p(0)$. <Strong duality> concerns optimal values; primal attainment additionally requires an actual minimizing point.