The study or science and art of number and letter manipulation. This would include geometric forms such as the Tetraktys of the Decad. "I {Jesus} have turned their (periods of) influence and their quadrangles and their triangles and their figures of eight , since their (periods of) influence remained turned to the left from the beginning, together with their quadrangles and their triangles and their figures of eight". ("Pistis Sophia", See also; Tetraktys of the Decad". See also; "Marsenes". )