Moreover, during these
years handbooks of Meftah ol Saadah and Meftah ol-Siyadah were published by an unknown author in the field of
mathematics and architecture (table5). Following Eric Schroeder, Oleg Grabar in his book "The Great Mosque of
Isfahan", believes that Khayyām Note 45 played a role in drawings resulted in creation of the north dome of Grand
Mosque of Isfahan. He sees him as its inventor (Graber, 1990).