“…It is also rich enough to allow building an intuition about the general case. In particular, in this class there are examples of Jacobi matrices with purely absolutely continuous spectrum filling the whole real line (see [15,17,35,38,41]), having a bounded gap in absolutely continuous spectrum (see [5-7, 9, 10, 12, 14, 19, 27]), having absolutely continuous spectrum on the half-line (see [4,8,16,18,[23][24][25][26]33]), having purely singular continuous spectral measure with explicit Hausdorff dimension (see [2]), having a dense point spectrum on the real line (see [2]), and having an empty essential spectrum (see [11,[29][30][31]42]).…”