If the owner's seal and epitaph are excavated in a tomb, it can be determined that the tomb is the real Tomb of the owner. In the Xigaoxue tomb, the seal and epitaph of Cao Cao are not excavated. 
the Xigaoxue tomb is not the real Tomb of Cao Cao.
If I have wings, I can fly. I have no wings, so I can't fly