Here are two other chapters from the Pact of Union (which I got from the same thread):
Article of Faith VIII
If someone does not anathematize Arius, Eunomius, Macedoinius, Apollinaris the hereitc, Nestorius, Eutyches of ill-repute, and Cyrus and John and Aegeotas and all who in whatever way, contradict the Twelve Chapters of the most holy Cyrill, and do not repent, but die in such error, and those who thought or think like them, let him be anathema.
Article of Faith IX
If someone does not anathematize the writings of Theodoret which are contrary to the right Faith of Cyril [now] among the saints, and the so-called Letter of Ibas, and Theodore of Mopsuestia and his writings, and if someone does not accept the writings of holy Cyril, and especially those against Thedore and Theodoret, and Andrew, and Nestorius and those who have thought or think like them or one of them, let him be anathema.
I think the problem with some Chalcedonians is that they so radically insist on a duality of energies, natures, and wills that they exclude other equally orthodox modes of Christological expression. Had the imperial Church accepted "one theandric will and energy" we might have reunited long ago.