Consider a directed graph $G$ and the associated Path-edge matrix $P_{i,j} \equiv \mathcal{X}(\text{edge $i$ contains path $j$})$, for $j\in \mathcal{P}$ (set of collection of all paths between pairs of vertices $\{(u_k,v_k)|k=1, \dots, K\}$) and $i\in E$ (the set of edges contained in $\mathcal{P}$). Here $\mathcal{X}$ represents the indicator function.
What is known about the rank of matrix P? Specifically, is it a full rank matrix for all connected graphs and all possible sets of vertex pairs?