Logic Symposia, Hakone, 1979, 1980 proceedings of conferences held in Hakone, Japan, March 21-24, 1979 and February 4-7, 1980 / edited by G.H. Muller, G. Takeuti, and T. Tugue. - Muller, G. H. (Gert Heinz), 1923-; Takeuti, Gaisi, 1926-; Tugue, T. (Tosiyuki), 1926- (Lecture notes in mathematics (Springer-Verlag) ;, 1981)