Question

Emily, a Filipino resident, owns a parcel of land located in the Philippines. She executes a will in Guam, a jurisdiction that applies the Doctrine of Renvoi. In her will, she bequeaths the said parcel of land to her niece, Sarah. Upon Emily's death, a dispute arises regarding the validity and interpretation of the will.

Sarah, as the beneficiary named in the will, files a petition for probate in the Philippines, seeking the recognition and implementation of the will. However, the lawyer representing the other heirs contests the application, arguing that the will should be governed by the Philippine laws, specifically the Lex Rei Sitae principle.

Advise the Philippine court on the following:

1. Whether the Doctrine of Renvoi should be applied in this case, considering Emily's execution of the will in Guam.
2. How the Doctrine of Processual Presumption could potentially affect the resolution of the dispute in the Philippines.
3. The relevance of the Lex Rei Sitae principle in determining the validity and interpretation of the will.