[1] Grzegorz Bancerek. The ordinal numbers. Formalized Mathematics, 1(1):91-96, 1990.Search in Google Scholar
[2] Andrzej Trybulec. Enumerated sets. Formalized Mathematics, 1(1):25-34, 1990.Search in Google Scholar
[3] Andrzej Trybulec. On the sets inhabited by numbers. Formalized Mathematics, 11(4):341-347, 2003.Search in Google Scholar
[4] Zinaida Trybulec. Properties of subsets. Formalized Mathematics, 1(1):67-71, 1990.Search in Google Scholar
