Positive constant scalar definition In French when we say "$k$ est une constante positive", that means $k\geq 0$. But I remarked that using the same sentence in English, "$k$ is a positive constant", means that $k>0$. Can one explain to me why$ k$ is a positive constant scalar doesn't include $0$?

Because the working convention is that "positive" is not the same as "not negative".
(There are other discrepancies between countries about terminology, which later were spread through the rest of the world.)
