Contents

Preface

IX

Program of invited talks

XI

Conference participants xii

Randomness in computability theory

KLAUS AMBOS-SPIES AND ANTONIN KUCERA

1

Open questions about the n-c.e. degrees

MARAT ARSLANOV

15

The theory of numberings: Open problems

8ERIKZHAN BADAEV AND 8ERGEY GONCHAROV

23

n~

classes - structure and applications

DOUGLAS CENZER AND CARL G. JOCKUSCH, JR.

39

The global structure of computably enumerable sets

PETER A. CHOLAK

61

Computability theory in arithmetic: Provability, structure and techniques

C.

T.

CHONG AND YUE YANG

73

How many Turing degrees are there?

RANDALL DOUGHERTY AND ALEXANDER 8. KECHRIS

83

Questions in computable algebra and combinatorics

ROD DOWNEY AND J. B. REMMEL

95

Issues and problems in reverse mathematics

HARVEY FRIEDMAN AND STEPHEN G. SIMPSON

127

Open problems in the theory of constructive algebraic systems

SERGEY GONCHAROV AND BAKHADYR KHOUSSAINOV

145

Independence results from ZFC in computability theory: Some open

problems

MARCIA G ROSZEK

171

Problems related to arithmetic

JULIA F. KNIGHT

181

vii