Pointed cone
= Pointed cone
{title2=$K\cap(-K)=\{0\}$}
A <convex cone> containing no nonzero line through the origin, equivalently $K\cap(-K)=\{0\}$. The <copositive cone> is pointed: a <matrix> in both it and its negative has zero <quadratic form> on the <nonnegative orthant>; testing $e_i$ and $e_i+e_j$ kills all entries.