Imagine we have the following set $A = \{a,b,c,d\}$ and we consider vectors which represent orders in that set. For example, I'd write $\vec{v} = (d,b,a,c)$ for the ordering $d > b > a > c$.
In this context, given an element $x$, is there a specific mathematical notation that allows me to get the index of elements $x$ in $\vec{v}$?
Following the example above, I'd like to get something like $f(\vec{v},a)=3$ and $f(\vec{v},d)=1$.