{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,1]],"date-time":"2026-03-01T13:45:35Z","timestamp":1772372735380,"version":"3.50.1"},"reference-count":10,"publisher":"Springer Science and Business Media LLC","issue":"3","license":[{"start":{"date-parts":[[1990,5,1]],"date-time":"1990-05-01T00:00:00Z","timestamp":641520000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/www.springer.com\/tdm"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Arch Math Logic"],"published-print":{"date-parts":[[1990,5]]},"DOI":"10.1007\/bf01621469","type":"journal-article","created":{"date-parts":[[2005,4,30]],"date-time":"2005-04-30T17:18:03Z","timestamp":1114881483000},"page":"171-180","source":"Crossref","is-referenced-by-count":45,"title":["Measure theory and weak K\u00f6nig's lemma"],"prefix":"10.1007","volume":"30","author":[{"given":"Xiaokang","family":"Yu","sequence":"first","affiliation":[]},{"given":"Stephen G.","family":"Simpson","sequence":"additional","affiliation":[]}],"member":"297","reference":[{"key":"CR1","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/0168-0072(86)90066-7","volume":"31","author":"D.K. Brown","year":"1986","unstructured":"Brown, D.K., Simpson, S.G.: Which set existence axioms are needed to prove the separable Hahn-Banach theorem? Ann. Pure Appl. Logic31, 123\u2013144 (1986)","journal-title":"Ann. Pure Appl. Logic"},{"key":"CR2","doi-asserted-by":"crossref","DOI":"10.1007\/978-1-4684-9440-2","volume-title":"Measure theory","author":"P.R. Halmos","year":"1950","unstructured":"Halmos, P.R.: Measure theory. New York: Van Nostrand 1950"},{"key":"CR3","doi-asserted-by":"crossref","first-page":"95","DOI":"10.2307\/2272348","volume":"39","author":"C.G. Jockusch Jr.","year":"1974","unstructured":"Jockusch, C.G., Jr.:\u03a0 \u03a0 1 0 classes and Boolean combinations of recursively enumerable sets. J. Symb. Logic39, 95\u201396 (1974)","journal-title":"J. Symb. Logic"},{"key":"CR4","first-page":"33","volume":"173","author":"C.G. Jockusch","year":"1972","unstructured":"Jockusch, C.G., Soare, R.I.:\u03a0 1 0 classes and degrees of theories. Trans. Am. Math. Soc.173, 33\u201356 (1972)","journal-title":"Trans. Am. Math. Soc."},{"key":"CR5","volume-title":"Real and complex analysis","author":"W. Rudin","year":"1966","unstructured":"Rudin, W.: Real and complex analysis. New York: McGraw-Hill 1966"},{"key":"CR6","doi-asserted-by":"crossref","unstructured":"Sacks, G.E.: Degrees of Unsolvability. Ann. Math. Stud.55, Princeton University Press, 1963","DOI":"10.1515\/9781400881840"},{"key":"CR7","unstructured":"Simpson, S.G.: Subsystems of Second Order Arithmetic. (in preparation)"},{"key":"CR8","first-page":"434","volume-title":"Subsystems of Z2 and reverse mathematics, appendix to Proof theory","author":"S.G. Simpson","year":"1986","unstructured":"Simpson, S.G.: Subsystems of Z2 and reverse mathematics, appendix to Proof theory, second edition, by G. Takeuti. Amsterdam: North-Holland, 1986, pp. 434\u2013448","edition":"second edition"},{"key":"CR9","doi-asserted-by":"crossref","first-page":"783","DOI":"10.2307\/2274131","volume":"49","author":"S.G. Simpson","year":"1984","unstructured":"Simpson, S.G.: Which set existence axioms are needed to prove the Cauchy\/Peano theorem for ordinary differential equations? J. Symb. Logic49, 783\u2013802 (1984)","journal-title":"J. Symb. Logic"},{"key":"CR10","unstructured":"Yu, X.: Measure theory in weak subsystems of second order arithmetic. Ph.D. Thesis, The Pennsylvania State University, 1987"}],"container-title":["Archive for Mathematical Logic"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1007\/BF01621469.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/article\/10.1007\/BF01621469\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1007\/BF01621469","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,4,7]],"date-time":"2020-04-07T05:06:02Z","timestamp":1586235962000},"score":1,"resource":{"primary":{"URL":"http:\/\/link.springer.com\/10.1007\/BF01621469"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1990,5]]},"references-count":10,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1990,5]]}},"alternative-id":["BF01621469"],"URL":"https:\/\/doi.org\/10.1007\/bf01621469","relation":{},"ISSN":["0933-5846","1432-0665"],"issn-type":[{"value":"0933-5846","type":"print"},{"value":"1432-0665","type":"electronic"}],"subject":[],"published":{"date-parts":[[1990,5]]}}}