Yue Yang
Department of Mathematics
National University of Singapore
Date: January 5, 2026 (Monday)
Time: 15:00–17:00
Venue: Zhixin Building, Room A115
Location: Shandong University, Central Campus
Abstract
Gödel once attempted to establish the consistency of classical number theory by means of computable functionals of finite types. In his view, abstract concepts such as computable functionals could be regarded as finitistic in a broader sense, although they are not finitistic in Hilbert’s original sense. See Gödel’s 1972 paper, “On an Extension of Finitary Mathematics Which Has Not Yet Been Used.” The first part of this talk will discuss finitism in Hilbert’s sense and Tait’s mathematical characterization of finitism. The second part will introduce joint work with my collaborators on computability at finite types and, taking this work as a starting point, examine in what sense the computable functionals mentioned above may be considered finitistic.
About the Speaker
Yue Yang graduated from the Department of Mathematics at Peking University in 1985 and received his Ph.D. in Mathematics from Cornell University in 1992. He has been a faculty member of the Department of Mathematics at the National University of Singapore since 1993. His research focuses on recursion theory (computability theory) and reverse mathematics within mathematical logic.