{ "id": "2108.03666", "version": "v1", "published": "2021-08-08T15:29:43.000Z", "updated": "2021-08-08T15:29:43.000Z", "title": "Are $\\mathfrak a$ and $\\mathfrak d$ your cup of tea? Revisited", "authors": [ "Saharon Shelah" ], "comment": "revisited version of arXiv:math/0012170", "categories": [ "math.LO" ], "abstract": "This is a revised version (of late 2020) of [Sh:700], which is arXiv:math/0012170 . First point is noting that the proof of Theorem 4.3 in [Sh:700], which says that the proof giving the consistency $ \\mathfrak{b} = \\mathfrak{d} = \\mathfrak{u} < \\mathfrak{a} $ also gives $ \\mathfrak{s} = \\mathfrak{d} $. The proof uses a measurable cardinal and a c.c.c. forcing so it gives large $ \\mathfrak{d} $ and assumes a large cardinal. Second point is adding to the results of \\S2,\\S3 which say that (in \\S3 with no large cardinals) we can force $ {\\aleph_1} < \\mathfrak{b} = \\mathfrak{d} < \\mathfrak{a}$. We like to have $ {\\aleph_1} < \\mathfrak{s} \\le \\mathfrak{b} = \\mathfrak{d} < \\mathfrak{a} $. For this we allow in \\S2,\\S3 the sets $ K_t $ to be uncountable; this requires non-essential changes. In particular, we replace usually $ {\\aleph_0}, {\\aleph_1} $ by $ \\sigma , \\partial $. Naturally we can deal with $ \\mathfrak{i} $ and similar invariants. Third we proofread the work again. To get $ \\mathfrak{s} $ we could have retained the countability of the member of the $ I_t$-s but the parameters would change with $ A \\in I_t$, well for a cofinal set of them; but the present seems simpler. We intend to continue in [Sh:F2009].", "revisions": [ { "version": "v1", "updated": "2021-08-08T15:29:43.000Z" } ], "analyses": { "keywords": [ "large cardinal", "first point", "second point", "non-essential changes", "similar invariants" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }