19/09/21 08:07:52.98 RSxZzkRi.net
>>393 補足
モストフスキ崩壊補題の原論文PDFが下記にあるね
”1949,?theorem 3”らしい
URLﾘﾝｸ(en.wikipedia.org)
Mostowski collapse lemma
(抜粋)
In mathematical logic, the Mostowski collapse lemma, also known as the Shepherdson?Mostowski collapse, is a theorem of set theory introduced by Andrzej Mostowski (1949,?theorem 3) and John Shepherdson (1953).
References
URLﾘﾝｸ(matwbn.icm.edu.pl)
Mostowski, Andrzej (1949), "An undecidable arithmetical statement" (PDF), Fundamenta Mathematicae, Institute of Mathematics Polish Academy of Sciences, 36 (1): 143?164