PRESIDENTIAL COMMISSION ON GOOD GOVERNMENT, JULIETA C. BERTUBEN, IDE C. TILLAH, EMMANUEL E. CRUZ, SERGIO OSMEÑA III, TIRSO ANTIPORDA JR., VICTOR S. ZIGA, LUIS M. MIRASOL, JR., AND JOSE Y. FERIA, PETITIONERS, VS. EDUARDO M. COJUANGCO JR., ENRIQUEZ M. COJUANGCO, MANUEL M. COJUANGCO, ESTELITO P. MENDOZA, AND GABRIEL L. VILLAREAL, RESPONDENTS