CHIEF OF HAMAS MOVEMENT'S POLITBUREAU KHALID MISHAAL HAS EXPRESSED OPTIMISM AS REGARDS WEDNESDAY'S ARAB SUMMIT IN RIYADH, STRESSING THE ARAB'S UNIFIED STANCE IN SUPPORT OF MAKKAH AGREEMENT BETWEEN THE PALESTINIAN FACTIONS. SPEAKING AT A PRESS BRIEFING ON THE FRINGES OF THE 5TH CONFERENCE OF AL-QUDS INTERNATIONAL FOUNDATION BEING HELD IN ALGIERS, HE SAID THE CONVENING OF THE SUMMIT IN RIYADH IS A GOOD OMEN FOR THE OUTCOME OF THE MEETING, PARTICULARLY AS THE KINGDOM OF SAUDI ARABIA SPONSORED THE RECENT MAKKAH AGREEMENT.