內容簡介top Studies in Weak Arithmetics 簡介 The field of Weak arithmetics is application of logical methods to Number Theory, developed by mathematicians, philosophers, and Theoretical Computer Scientists. In this volume, after a general presentation of weak arithmetics, the following topics are studied: the properties of integers of a real closed field equipped with exponentiation; conservation results for the induction schema restricted to first-order formulas with a finite number of alternations of quantifiers; a survey on a class of tools, called pebble games, used in finite model theory; the fact reals and π have approximations expressed by first order formulas using bounded quantifiers; properties on infinite pictures depending on the universe of sets used; a language that simulates in a sufficiently nice manner all algorithms of a certain restricted class; the logical complexity of the axiom of infinity in some variants of set theory without the axiom of foundation; and the complexity to determine whether a trace is included in another one.