Transfer and a supremum principle for ERNA
Transfer and a supremum principle for ERNA
复制标题
ERNA 的转移和最高原则
DOI:
10.2178/jsl/1208359067
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发表时间:
2008
影响因子:
0.6
通讯作者:
Sam Sanders
中科院分区:
文献类型:
--
作者:
C. Impens;Sam Sanders
Abstract Elementary Recursive Nonstandard Analysis, in short ERNA, is a constructive system of nonstandard analysis proposed around 1995 by Patrick Suppes and Richard Sommer, who also proved its consistency inside PRA. It is based on an earlier system developed by Rolando Chuaqui and Patrick Suppes, of which Michal Rössler and Emil Jeřábek have recently proposed a weakened version. We add a Πı-transfer principle to ERNA and prove the consistency of the extended theory inside PRA. In this extension of ERNA a Σı-supremum principle ‘up-to-infinitesimals’, and some well-known calculus results for sequences are deduced. Finally, we prove that transfer is ‘too strong’ for finitism by reconsidering Rössler and Jeřábek's conclusions.