Classifying topoi and finite forcing
نویسندگان
چکیده
منابع مشابه
Classifying topoi and the axiom of infinity
Let 6 e be an elementary topos. The axiom of infinity, asserting that 5 e has a natural numbers object, is shown to be necessary-sufficiency has long been k n o w n f o r the existence of an object-classifying topos over 5 e. In the known constructions [1, 4, 6] of classifying topoi for geometric theories, it is always assumed that the base topos fie satisfies the axiom of infinity. The purpose...
متن کاملClassifying fuzzy normal subgroups of finite groups
In this paper a first step in classifying the fuzzy normalsubgroups of a finite group is made. Explicit formulas for thenumber of distinct fuzzy normal subgroups are obtained in theparticular cases of symmetric groups and dihedral groups.
متن کاملCLASSIFYING FUZZY SUBGROUPS OF FINITE NONABELIAN GROUPS
In this paper a rst step in classifying the fuzzy subgroups of a nite nonabelian group is made. We develop a general method to count the number of distinct fuzzy subgroups of such groups. Explicit formulas are obtained in the particular case of dihedral groups.
متن کاملForcing with finite conditions
We present a generalisation to ω2 of Baumgartner’s forcing for adding a CUB subset of ω1 with finite conditions. The following well-known result appears in Baumgartner, Harrington, Kleinberg [2]. For the reader’s convenience we provide a proof here. Theorem 1 Suppose that X ⊆ ω1. Then the following are equivalent: a. X contains a CUB subset in an outer model which preserves ω1. b. X is stationa...
متن کاملForcing Axioms, Finite Conditions and Some More
We survey some classical and some recent results in the theory of forcing axioms, aiming to present recent breakthroughs and interest the reader in further developing the theory. The article is written for an audience of logicians and mathematicians not necessarily familiar with set theory.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 1983
ISSN: 0022-4049
DOI: 10.1016/0022-4049(83)90085-3