Review: S. Shelah, Classification Theory and the Number of Nonisomorphic Models
Review: S. Shelah, Classification Theory and the Number of Nonisomorphic Models
复制标题
评论:S. Shelah,分类理论和非同构模型的数量
DOI:
10.2307/2273599
复制
发表时间:
1982
影响因子:
0.6
通讯作者:
V. Harnik
中科院分区:
文献类型:
--
作者:
V. Harnik
(among other places) when the negation rule (from A, B \C to infer A\ B, C) is added. This extends the shared bivalence assumption for atomic sentences to the intuitionistically unacceptable bivalence assumption for the language as a whole. Individually, and especially collectively, these papers deepen our understanding of the classical and inferential logical operations and suggest that proof-theoretic studies provide another battleground for general issues in the philosophy of logic. The authors are far from agreement on terminology, let alone philosophical conclusions. They also show that the following proof-theoretically trivial remark bears different interpretations: Put neutrally, natural-deduction systems are equivalent to Gentzen systems with the strong non-local condition that no side formulas appear on the right of the consequence symbol. But does this mean that natural-deduction systems are Gentzen systems with an ad hoc assumption, or that Gentzen systems are an unnatural extension of natural-deduction systems? RICHARD E. GRANDY