I am looking for the right name of a function of "linear variables".
I define function $f(x_1,x_2,x_3...)$ has "linear variables", if and only if here exists functions $f_1, f_2, f_3...$ such that $f(x_1,x_2,x_3...)=f_1(x_1)+f_2(x_2)+f_3(x_3)...$.
In other words, the the variables are "uncorrelated" to each other, but still can take different functional forms.
Is there a right name for this? Thanks!
