- Jean-Pierre Ressayre:
**Weak Arithmetics.**1-15

- Denis Richard:
**What are weak arithmetics?**17-29

- Patrick Cégielski, Denis Richard:
**Decidability of the theory of the natural integers with the cantor pairing function and the successor.**51-77

- Costas Dimitracopoulos:
**On end extensions of models of subsystems of peano arithmetic.**79-84

- Jacques Duparc, Olivier Finkel, Jean-Pierre Ressayre:
**Computer science and the fine structure of Borel sets.**85-105

- Henri-Alex Esbelin:
**Counting modulo finite semigroups.**107-114

- Ivan Korec:
**A list of arithmetical structures complete with respect to the first-order definability.**115-151

- Maurice Margenstern:
**On quasi-unilateral universal Turing machines.**153-166

- Yuri Matiyasevich:
**Some arithmetical restatements of the Four Color Conjecture.**167-183

- Olivier Sudac:
**The prime number theorem is PRA-provable.**185-239

- Olivier Teytaud:
**Decidability of the halting problem for Matiyasevich deterministic machines.**241-251