Al-Kindi
Abu Yusuf Yaqub ibn Ishaq al-Sabbah Al-Kindi (801 - 873) worked with Al-Khawarizmi and the Banu Musa Brothers to translate Greek scientific manuscripts in the "House of Wisdom" in Baghdad. In addition, Al-Kindi wrote many manuscripts and books of his own. Topics for these manuscripts included:
- Indian numbers
- The harmony of numbers
- Astrology
- Lines and multiplication with numbers
- Relative quantities
- Numerical procedures and cancellation
- The theory of parallel lines (and in particular lines which are non-intersecting and non-parallel)
- The first treatise on cryptanalysis.
