Working in the theory ”ZF + There is a nontrivial elementary embedding j : V → V“, we show that a final segment of cardinals satisfies certain square bracket finite and infinite exponent partition relations. As a corollary to this, we show that this final segment is composed of Jonsson cardinals. We then show how to force and bring this situation down to small alephs. A prototypical result is the construction of a model for ZF in which every cardinal μ ≥ ℵ2 satisfies the square bracket infinite exponent partition relation . We conclude with a discussion of some consistency questions concerning different versions of the axiom asserting the existence of a nontrivial elementary embedding j: V → V. By virtue of Kunen's celebrated inconsistency result, we use only a restricted amount of the Axiom of Choice.

The Ladd-Franklin “antilogism” provides a very convenient procedure for testing syllogistic arguments, especially when they are expressed algebraically. It is well known, however, that the antilogism test indicates the invalidity of certain moods which the traditional logic regards as valid. These are the moods in which a particular conclusion is inferred from two universal premises. It is the aim of this paper to show that the antilogism can be generalized in such a way as to cover these moods, and also to be applicable to certain forms of “immediate inference” and “sorites,” as these designations have been traditionally employed.

We shall find that when generalized in this fashion there are two principal kinds of antilogisms: (1) those which include an inequation of the form ab≠0, and (2) those which include an inequation of the form a≠0.

Definition. An antilogism is a group of propositions so constructed that the contradictory of any one of them is implied by the logical product of the others.

In this article, a notion of Schauder equivalence relation ℝℕ/L is introduced, where L is a linear subspace of ℝℕ and the unit vectors form a Schauder basis of L. The main theorem is to show that the following conditions are equivalent:

(1) the unit vector basis is boundedly complete;

(2) L is a Fσ in ℝℕ;

(3) ℝℕ/L is Borel reducible to ℓ∞.

We show that any Schauder equivalence relation generalized by a basis of ℓ2 is Borel bireducible to ℝℕ/ℓ2 itself, but it is not true for bases of c0 or ℓ1. Furthermore, among all Schauder equivalence relations generated by sequences in c0, we find the minimum and the maximum elements with respect to Borel reducibility.

We explore the structural properties of the inner model L(Vδ+1) under the assumption that δ is a singular limit of Berkeley cardinals each of which is itself limit of extendible cardinals, lifting some of the main results of the theory of the axiom I0 to the level of Berkeley cardinals, the strongest known large cardinal axioms. Berkeley cardinals have been recently introduced in [1] and contradict the Axiom of Choice.1 In fact, our background theory will be ZF.

Let X be an infinite but separable metric space. An open cover of X is said to be large if for each x ϵ X the set {U ϵ : x ϵ U} is infinite. The symbol Λ denotes the collection of large open covers of X. An open cover of X is said to be an ω-cover if for each finite subset F of X there is a U ϵ such that F ⊆ U, and X is not a member of , X is said to have Rothberger's property if there is for every sequence (n : n = 1,2,3,…) of open covers of X a sequence (Un : n = 1,2,3,…) such that:

(1) for each n, Un is a member of n, and

(2) {Un: n = 1,2,3,…} is a cover of X.

Rothberger introduced this property in his paper [2]. For convenience we let denote the collection of all open covers of X.

In [3] it was shown that X has Rothberger's property if, and only if, the following partition relation is true for large open covers of X:

This partition relation means:

for every large cover of X, for every coloring

such that for each U ϵ and each large cover there is an i with a large cover of X,

either there is a large cover such that f({A, B}) = 0 whenever {A,B} ϵ ,

or else there is a which is not point–finite such that f{{A, B}) = 1 whenever {A, B} ϵ .

In [5] S. S. Wainer introduces a hierarchy for arbitrary type-2-functionals. Given F, he defines a set of ordinal notations OF, and for each a ∈ OF, a function fa recursive in F and an ordinal ∣a∣F < For any f recursive in F there is an a ∈ OF such that f is primitive recursive in fa.

Let ρF be the least ordinal α such that for any f recursive in F there is an α ∈ OF with ∣a∣F ≤ α such that f is primitive recursive in fa. If ρF < the hierarchy breaks down. In Bergstra and Wainer [2] ρF is described as “the real ordinal of the 1-section of F”.

Using standard methods (originally due to Kleene) one may prove that if F is normal, then ρF = Feferman has proved that if F is recursive, then ρF = ω2.

Let 1-section (F) = l-sc(F) = {f; f is recursive in F} where f is a total object of type 1.

Grilliot [4] proved that F ↾ 1-sc(F) is continuous if and only if F is not normal.

Let h be an associate for a given functional F, and assume that h is recursive in the jump of an element of 1-sc(F).

Let L = 〈<, +, hq, 1〉q∈ℚ where ℚ is the set of rational numbers and hq is a one-place function symbol corresponding to multiplication by q. Then the L-theory of Scott's model for intuitionistic analysis is decidable.

The purpose of this note is to demonstrate that a weak form of club guessing on ω1 implies the existence of an Aronszajn line with no Countryman suborders. An immediate consequence is that the existence of a five element basis for the uncountable linear orders does not follow from the forcing axiom for ω-proper forcings.

The purpose of the present paper is to introduce a generalisation of the concept of productive set introduced by Post (2) and studied by Dekker (3) and others. Throughout the paper we shall use small Latin letters to denote both non-negative integers (referred to as numbers) and functions (both partial and total) from numbers to numbers. Sets of numbers will be denoted by small Greek letters and classes of such sets by capital Latin letters. ωη is the range of the ηth partial recursive function.