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Adjoining Almost Disjoint Permutations
Author(s) -
Zhang Yi
Publication year - 2002
Publication title -
mathematical logic quarterly
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.473
H-Index - 28
eISSN - 1521-3870
pISSN - 0942-5616
DOI - 10.1002/1521-3870(200202)48:2<189::aid-malq189>3.0.co;2-g
Subject(s) - disjoint sets , mathematics , combinatorics , maxima , permutation (music) , ask price , discrete mathematics , philosophy , history , economy , performance art , economics , art history , aesthetics
We show that it is consistent with ZFC + ¬CH that there is a maxima a most disjoint permutation family A ⊆ Sym(ℕ)such that A is a proper subset of an eventually different family E ⊆ ℕ ℕ and | A | < | E |. We also ask severa questions in this area.