Hyperequational Theory forpartial algebrasSaofee BusamanUniversit¨at Potsdam, 2006Institut fur¨ MathematikHyperequational Theory for partial algebrasDissertationzur Erlangung des akademischen GradesDoktor der Naturwissenschaften(Dr. rer. nat.)in der Wissenschaftsdisziplin Algebraeingereicht an derMathematisch-Naturwissenschaftlichen Fakultat¨der Universit¨ at PotsdamvonSaofee Busamangeboren am 10.03.1971 in ThailandPotsdam, 2006This work is dedicated to my parentsSuntik Busaman and Nieyand Busaman,for their love and support throughout my life.ivAcknowledgementsI would like to first thank Professor Dr. K. Denecke, who introduced me toresearch, useful suggestions and encouragement throughout this work.I gratefully acknowledge the financial support of ‘Royal Thai Government Schol-arship’.I would like to thank Professor Dr. H-J. Vogel, Dr. J. Koppitz and Dr. M.Fritzsche for various recommendations during research seminars; Frau W. Kruegerfor their daily help.It is a pleasure to record thanks to Dr. Srichan Arworn (Chaing Mai University),who made it possible for me to know Prof. K. Denecke and for her unfailing help.I express my family to my wife Ratchanida Busaman to my son Sareef Busamanand to my daughter Feerada Busaman for their understanding and encouragement.Finally, thanks are due to all of the staff in the Institute of Mathematics andthe International Relations office at Potsdam University Germany, for there wormwelcome.S.