Invitation to the Logic Seminar at the National University of Singapore

Date: Wednesday, 19 November 2014, 17:00 hrs

Room: S17#04-04, Department of Mathematics, NUS

Speaker: Dan Teng

Title: Semiautomatic Structures

URL: http://www.comp.nus.edu.sg/~fstephan/logicseminar.html

Semiautomatic structures generalise automatic structures in the sense

that for some of the relations and functions in the structure one only

requires the derived relations and structures are automatic when all

but one input are filled with constants. One can also permit that this

applies to equality in the structure so that only the sets of

representatives equal to a given element of the structure are regular

while equality itself is not an automatic relation on the domain of

representatives. It is shown that one can find semiautomatic

representations for the field of rationals and also for finite

algebraic field extensions of it. Furthermore, it is shown that there

are semiautomatic ordered rings consisting of the integers augmented

by the multiples of the square-root of a non-square integer; here the

order is the same as the corresponding order on the real numbers.