XI. John and Paula, British citizens at birth, acquired Philippine citizenship by naturalization after their marriage. During their marriage the couple acquired substanial landholdings in London and in Makati. Paula bore John three children, Peter, Paul and Mary. In one of their trips to London, the couple executed a joint will appointing each other as their heirs and providing that upon the death of the survivor between them the entire estate would go to Peter and Paul only but the two could not dispose of nor divide the London estate as long as they live. John and Paul died tragically in the London Subway terrorist attack in 2005. Peter and Paul filed a petition for probate of their parent's will before a Makati Regional Trial Court. Should the will be admitted to probate? (2%) Are the testamentary dispositions valid? (2%) Is the testamentary prohibition against the division of the London estate valid? (2%)