I have a vector of vectors that can be described as:
${A} = \left(a_i \right)_{i=1}^{N}$
I want to discard some of its elements based on some conditions, how can formulate it?
For instance, I have:
${A^R}=(a \mid \forall a \in {A} \wedge a \in \mathcal{A}^R)$
To denote the vector which only keeps the elements that are contained in the set $\mathcal{A}^R$ and eliminates all other elements.
Is there a better formulation for it?