Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Fourth Ecumenical Council.  The Council of Chalcedon.: Extracts from the Acts.  Session II. (Continued).

Extracts from the Acts.

Session II.  (Continued).

(L. and C., Conc., Tom. IV., col. 343.)

And when these letters [i.e. Cyril’s letter to Nestorius Καταφλυαροῦσι and his letter to John of Antioch Εὐφραινέσθωσαν] had been read, the most reverend bishops cried out:  We all so believe:  Pope Leo thus believes:  anathema to him who divides and to him who confounds:  this is the faith of Archbishop Leo:  Leo thus believes:  Leo and Anatolius so believe:  we all thus believe.  As Cyril so believe we, all of us:  eternal be the memory of Cyril:  as the epistles of Cyril teach such is our mind, such has been our faith:  such is our faith:  this is the mind of Archbishop Leo, so he believes, so he has written.

The most glorious judges and the great senate said:  Let there be read also the epistle of the most worthy Leo, Archbishop of Old Rome, the Imperial City.

Beronician, the most devout clerk of the sacred consistory, read from a book handed him by Aëtius, Archdeacon of the holy Church of Constantinople, the encyclical or synodical letter of the most holy Leo, the Archbishop, written to Flavian, Archbishop of Constantinople.