Abstract:
Let $E$ be an ordered normed space and $X$ be an arbitrary normed space. The following two crossnorms are considered: for
\begin{gather*}
n_E(z)=\inf\biggl\{\|u\|:\sum_{k=1}^ne_k\langle x_k,x^*\rangle\le u,\ z=\sum_{k=1}^ne_k\otimes x_k,\ x^*\in X,\ \|x^*\|\le1\biggr\},
\\
k_E(z)=\inf\biggl\{\biggl\|\sum_{k=1}^ne_k\|x_k\|\biggr\|:z=\sum_{k=1}^ne_n\otimes x_k,\ e_k\ge0\biggr\}.
\end{gather*}
Theorem 1.The following conditions are equivalent:
1) for every normed space $X$ and every $z\in E\otimes X$ we have $n_E(z)=k_E(z)$.
2)$E$ has the Riesz interpolation property.