Nonstandard arithmetic and reverse mathematics

We show that each of the five basic theories of second order arithmetic that play a central role in reverse mathematics has a natural counterpart in the language of nonstandard arithmetic. In the earlier paper [HKK1984] we introduced saturation principles in nonstandard arithmetic which are equivalent in strength to strong choice axioms in second order arithmetic. This paper studies principles which are equivalent in strength to weaker theories in second order arithmetic.

• Type: Journal
• Year: 2006
• Where: BSL
• Authors: H. Jerome Keisler
• Keywords: Basic Theories, BSL 2006, Nonstandard Arithmetic, Order Arithmetic