Akbar Pourgholam
(1), Masoud Sabbaghan
(2), Fatemeh Taleghani
(3)
(1)
Department of Pure Mathematics, Faculty of Mathematical Sciences,9 Lahijan Branch, Islamic Azad University, Lahijan, IRAN, Iran, Islamic Republic of,
(2)
Department of Pure Mathematics, Faculty of Mathematical Sciences,
Lahijan Branch, Islamic Azad University, Lahijan, IRAN, Iran, Islamic Republic of,
(3)
Department of Pure Mathematics, Faculty of Mathematical Sciences,Lahijan Branch, Islamic Azad University, Lahijan, IRAN, Iran, Islamic Republic of