I'm having problem understanding the min weight st-cut integer programming in this wiki page: https://en.wikipedia.org/wiki/Max-flow_min-cut_theorem
In the min-cut dual part, it has
$$d_{ij}-p_i+p_i \geq 0 \;\; \forall (i,j) \in E$$ where $d_{ij}$ is binary: 1 if the edge is selected in st-cut 0 otherwise. p_i is 1 if vertex i is in the same side as s and 0 if in the same side as p. (you can read the original wiki for more information).
I'm not able to understand how this constraint will make this IP work.