Chellas, Brian F.Nagle, Michael Colahan2005-07-212005-07-211981NL Number: 60815http://hdl.handle.net/1880/22540Bibliography: p. 134-136.iv, 136 leaves ; 30 cm.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.BC 199 M6 N33 1984Modality (Logic)Logic, Symbolic and mathematicaldoctoral thesis10.11575/PRISM/18351BC 199 M6 N33 1984