 Nevertheless, the introduction of the  Demonstrative Figure  in Ars demostrativa is particularly meaningful, for it synthesizes the other figures and makes their relationship dynamic. The Demonstrative Figure is formed by six circles, and it includes a mechanism that allows the circles to rotate. At the center, Llull places a triangle, as those found in  Figure T.  The first two circles correspond to the  Elemental Figure,  the following two, with seven letters, represent Figures A, S, T, V, X, Y, Z. The last two circles have the letters B–R that are the terms of  Figure S,  but Figures A, T, V, X as well, and other two figures, the Principles of Theology and the Principles of Philosophy, which are introduced when the operation of the Art is extended to both fields.