inputs: hypothesis: Sheikh Osama bin Laden and Sheikh Ayman al-Zawahri are the leaders of al Qaeda. premise: It said it carried out both the Taba and Sharm el-Sheikh attacks "in obedience to the leaders of jihad (holy war) in al Qaeda, Sheikh Osama bin Laden and Sheikh Ayman al-Zawahri" and to avenge the "oppressed brothers in Iraq and Afghanistan".