Assuming that ∀x Є ω^ω (x^# exists), let u_ɑ be the ɑth uniform indiscernible (see [3] or [2] ). A canonical coding system for ordinals < u_ω can be defined by letting W0_ω = {w Є ω^ω: w = (n, x^#), for some n Є ω, x Є ω^ω} and for w = (n, x^#) є W0_ω, │w│ = Ƭ^L_n [x](u_l',... , u_k_n), where T_n is the nth term in a recursive enumeration of all terms in the language of ZF + V = L [x], x a constant, taking always ordinal values. Call a relation P(ξ x), where ~varies over u^ω and x over ω^ω, ∏^1_k if P^*(w, x)⇔ w Є W0_ω Λ P(│w│, x) is ∏^1_k. An ordinal ξ < u_ω is called Δ^1_k if it has a Δ^1_k notation i.e. ∃ w Є W0_ω (w Є Δ^1_k Λ │w│ = ξ)
Let ω = {0, 1, 2, ... } be the set of natural numbers and R = ω^ω the set of all infinite sequences ...
We study in this paper the projective ordinals δ^1_n, where δ^1_n = sup{ξ: ξ is the length of ɑ Δ^1_...
AbstractThe paper presents a uniform way of obtaining by forcing descending sequences of the iterati...
Assuming that ∀x Є ω^ω (x^# exists), let u_ɑ be the ɑth uniform indiscernible (see [3] or [2] ). A c...
A very important part of the structure theory of Σ^1_2 sets of reals is based on their close interre...
A very important part of the structure theory of Σ^1_2 sets of reals is based on their close interre...
The following results are proved, using the axiom of Projective Determinacy: (i) For n ⪴ 1, every ∏^...
In this paper we give an ordinal analysis of a set theory extending ${\sf KP}\ell^{r}$ with an axiom...
AbstractIn this paper, we give two proofs of the wellfoundedness of a recursive notation system for ...
AbstractWe show, using the fine structure of K(R), that the theory ZF + AD + ∃X ⊆ R[X ∉ K(R)] implie...
The paper focuses on the structure of fundamental sequences of ordinals smaller than $e$. A first re...
The notion of ordinal computability is dened by generalising standard Turing computability on tapes ...
In recent work Woodin has defined new axioms stronger than I0 (the existence of an elementary embedd...
Let ω = {0, 1, 2, ... } be the set of natural numbers and R = ω^ω the set of all infinite sequences ...
The following results are proved, using the axiom of Pro-jective Determinacy: (i) For n ̂ 1, every ...
Let ω = {0, 1, 2, ... } be the set of natural numbers and R = ω^ω the set of all infinite sequences ...
We study in this paper the projective ordinals δ^1_n, where δ^1_n = sup{ξ: ξ is the length of ɑ Δ^1_...
AbstractThe paper presents a uniform way of obtaining by forcing descending sequences of the iterati...
Assuming that ∀x Є ω^ω (x^# exists), let u_ɑ be the ɑth uniform indiscernible (see [3] or [2] ). A c...
A very important part of the structure theory of Σ^1_2 sets of reals is based on their close interre...
A very important part of the structure theory of Σ^1_2 sets of reals is based on their close interre...
The following results are proved, using the axiom of Projective Determinacy: (i) For n ⪴ 1, every ∏^...
In this paper we give an ordinal analysis of a set theory extending ${\sf KP}\ell^{r}$ with an axiom...
AbstractIn this paper, we give two proofs of the wellfoundedness of a recursive notation system for ...
AbstractWe show, using the fine structure of K(R), that the theory ZF + AD + ∃X ⊆ R[X ∉ K(R)] implie...
The paper focuses on the structure of fundamental sequences of ordinals smaller than $e$. A first re...
The notion of ordinal computability is dened by generalising standard Turing computability on tapes ...
In recent work Woodin has defined new axioms stronger than I0 (the existence of an elementary embedd...
Let ω = {0, 1, 2, ... } be the set of natural numbers and R = ω^ω the set of all infinite sequences ...
The following results are proved, using the axiom of Pro-jective Determinacy: (i) For n ̂ 1, every ...
Let ω = {0, 1, 2, ... } be the set of natural numbers and R = ω^ω the set of all infinite sequences ...
We study in this paper the projective ordinals δ^1_n, where δ^1_n = sup{ξ: ξ is the length of ɑ Δ^1_...
AbstractThe paper presents a uniform way of obtaining by forcing descending sequences of the iterati...