chapter  10
36 Pages

Peano Arithmetic PA and its Expansion PR

The structure of this Chapter is simple; there is only one language being considered and only one axiom system, that of Peano arithmetic. In Section 1 a few mathematical statements will be derived from these axioms, and some of these proofs will be carried out using only intuitionistic logic, in which case Peano arithmetic is also called Heyting arithmetic H A .