A Note on Non-Distributive Sublattices of Degrees and Hyperdegrees
Canadian journal of mathematics, Tome 21 (1969) no. 1, pp. 147-148
Voir la notice de l'article provenant de la source Cambridge University Press
In (1, §§ 2.3 and 2.4) we proved that certain distributive lattices are simultaneously lattice-embeddable in the degrees of recursive unsolvability and in the hyperdegrees. Let L be the non-distributive lattice {0,1, a 0, a 1,...}, where ai ∪ aj = 1 and ai ∩ aj = 1 whenever i ≠ j. We shall prove the following theorem.THEOREM. The lattice L is simultaneously lattice-embeddable in the degrees and hyperdegrees.For A ⊆ N, let deg(A) and hyp(A) be the degree and hyperdegree of A, respectively. To prove the theorem we must construct hyperarithmetically incomparable sets A 0, A 1, ... such that for Δ = deg, hypand for all distinct i, j: 1 2 Now, if each 〈Ai , Aj 〉 were a generic pair in the sense of (1), then (2) would hold.
Thomason, S. K. A Note on Non-Distributive Sublattices of Degrees and Hyperdegrees. Canadian journal of mathematics, Tome 21 (1969) no. 1, pp. 147-148. doi: 10.4153/CJM-1969-013-2
@article{10_4153_CJM_1969_013_2,
author = {Thomason, S. K.},
title = {A {Note} on {Non-Distributive} {Sublattices} of {Degrees} and {Hyperdegrees}},
journal = {Canadian journal of mathematics},
pages = {147--148},
year = {1969},
volume = {21},
number = {1},
doi = {10.4153/CJM-1969-013-2},
url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-1969-013-2/}
}
TY - JOUR AU - Thomason, S. K. TI - A Note on Non-Distributive Sublattices of Degrees and Hyperdegrees JO - Canadian journal of mathematics PY - 1969 SP - 147 EP - 148 VL - 21 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1969-013-2/ DO - 10.4153/CJM-1969-013-2 ID - 10_4153_CJM_1969_013_2 ER -
[1] 1. Thomason, S. K., The forcing method and the upper semi-lattice of hyperdegrees, Trans. Amer. Math. Soc. 129 (1967), 38–57. Google Scholar
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