On these basic elements, which overlap each other with a slight backslash and with an ever larger surface finish, the straight edge is set to perfectly polished alternating bands, similar to the opus quadratum pseudoisodomum of the ancient buildings.

The second projection line from the top, due to the late elevation of the church, does not correspond today to any structural element, but originally combined the terminal capitals (dark green) of the lower angular risers.

This interpenetration of a static, geometric system can also be seen in the arches within the church, where the white and coloured stone is arranged symmetrically throughout, as is found in sixth and seventh century buildings such as the Mausoleum of Theodoric in Ravenna and the Dome of the Rock in Jerusalem (or in peristyle of Diocletian's Palace in Split, ca.

As is also to be seen in the early Christian basilicas in Rome, the interior of the church is divided into functional areas and crossed by a liturgical route which is clearly indicated, down to the smallest detail, by variations in the colour of the marble and by the different types of capital in pairs which match across the nave.

There are further reminders in the taste for varietas which (in the same strictly symmetrical context) informs all the sculpted ornamentation, whose careful variations have parallels in the Basilica of San Salvatore in Spoleto and in the capitals of the Temple of Saturn in Rome, rebuilt in the fourth century A.D.