A zairja was a device used by medieval Arab astrologers to calculate ideas by mechanical means. It used the 28 letters of the Arabic alphabet to signify 28 categories of philosophic thought. By combining number values associated with the letters and categories, new paths of insight and thought were created. An astrologer practices one or more forms of astrology. ... The Arabic alphabet is the script used for writing Arabic and various other languages, together with various closely related scripts that typically differ in the presence or absence of a few letters. ...

It is thought that Spanish mystic, Ramon Llull (1234-1315) in his travels and studies of Arab culture, became familiar with the zairja, and used it as a prototype for his invention of the Ars Magna (The Great Art). Ramon Llull. ... Ramon Llull. ...

Sources:

• Ramon Llull and Ars Magna
• Mind as Mosaic, The Robot in the Machine, Bruce H. Hinrichs, pp. 196-197