Pope Sylvester II [Gerbert of Aurillac] and Transubstantiation

Q. Did Pope Sylvester II [Gerbert of Aurillac], advocate the modern Roman dogma of transubstantiation?

Pope Sylvester II [Gerbert of Aurillac](c.  946 - 1003 A.D.):

J. H. Treat:

This Archbishop, afterwards Bishop of Rome, under the name of Sylvester II., wrote a short treatise, De corpore et sanguine Domini, in which he treats both sides of the controversy with singular moderation and impartiality. He probably did not believe in the new doctrine of Transubstantiation. Mabillon speaks of him under the name of Anonymus, as follows: 

Though this anonymus writer was  plainly possessed of ordinary ability and general knowledge, yet it must be confessed that his testimony avails but little for illustrating the controversies of the  ninth and tenth centuries, particularly if it be certain that he lived in the tenth century, as some think. —He teaches four things especially concerning these controversies: First, that Rabanus, Archbishop of Mentz, and Ratramnus wrote against the opinion of Paschasius, who asserted that in the Eucharist was the same body which was born of the Virgin Mary, which this anonymus writer also assails. —Fourth, that the body and blood of Christ are nevertheless truly contained in the Eucharist. 

(J. P. Minge, Patrologiæ Cursus Completus, [1880], Patrologiæ Latinæ, Tomus CXXXIX, Gerberti Postmodum Silvestri II Papæ Libellus De Corpore Et Sanguine Domini, Col. 177-178). Here Trans. (J. H. Treat, The Catholic Faith; Or, Doctrines of the Church of Rome Contrary to Scripture and the Teaching of the Primitive Church, [1888], p. 245). Here

Compare with:

The Westminster Confession of Faith. A.D. 1647.

Chapter XXIX - Of the Lord's Supper.

Section VII.

Worthy receivers, outwardly partaking of the visible elements in this sacrament, do then also inwardly by faith, really and indeed, yet not carnally and corporally, but spiritually, receive and feed upon Christ crucified, and all benefits of his death: the body and blood of Christ being then not corporally or carnally in, with, or under the bread and wine; yet as really, but spiritually, present to the faith of believers in that ordinance, as the elements themselves are, to their outward senses. 

(Philip Schaff, Creeds of Christendom, Vol. III, The Westminster Confession of Faith. A.D. 1647. Ch. XXIX, § VII). Here

~ Soli Deo Gloria