Consider the vector-valued function $f_{\psi, u, b} : R^d \to R$ of the form $$ f_{\psi, u, b}(x) := \psi(ux - b) $$ where $\psi: R \to R$, as well as $u \in R^d$ and $b \in R$, for any $x \in R^d$.
How to find the derivative of $f$ w.r.t $v \in R^d$?
Tnx.
Reference. Proposition 3's proof in https://arxiv.org/pdf/2006.02855.pdf