Both the arguments of the PER-SOC relation should be PER. A sentence can be "Paris, John’s sister, is staying in New York." The entity extractor identifies two mentions John and Paris and also predicts entity types for these mentions. But we can know that Paris is highly not possible to be a PER. So it violates the ground constraint. Hence the global decision which satisfies all the specified constraints would be to label both the mentions as PER and mark the PER-SOC relation between them.