Some relations for quasiunit regular rings and QB-rings, as well as for pseudounit regular rings and QB ∞-rings, are obtained. In the first part of the paper, we prove that (an exchange ring R is a QB-ring) ⟺ (whenever x ∈ R is regular, there exists a quasiunit regular element w ∈ R such that x = xyx = xyw for some y ∈ R) ⟺ (whenever aR + bR = dR in R; there exists a quasiunit regular element w ∈ R such that a + bz = dw for some z ∈ R). Similarly, we also give necessary and sufficient conditions for QB ∞-rings in the second part of the paper.
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References
P. Ara, K. R. Goodeal, K. C. O’Meara, and E. Pardo, “Separative cancellation for projective modules over exchange rings,” Isr. J. Math., 105, 105–137 (1998).
P. Ara, G. K. Pedersen, and F. Pereva, “An infinite analogue of rings with stable range one,” J. Algebra, 230, 608–655 (2000).
R. Camps and P. Menal, “Power cancellation for Artinian modules,” Commun. Algebra, 19, 2081–2095 (1991).
M. J. Canfell, “Completions of diagrams by automorphism and Bass’ first stable range condition,” J. Algebra, 176, 480–513 (1995).
H. Chen, “On exchange QB-rings,” Commun. Algebra, 31, 831–841 (2003).
H. Chen, “On QB ∞-rings,” Commun. Algebra, 34, 2057–2068 (2006).
H. Chen, “On exchange QB ∞-rings,” Alg. Colloq., 14, 613–623 (2007).
R. B. Warfield, Jr., “Exchange rings and decompositions of modules,” Math. Ann., 199, 31–36 (1972).
J. Wei, “Unit-regularity and stable range conditions,” Commun. Algebra, 33, 1937–1946 (2005).
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Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 64, No. 3, pp. 415–425, March, 2012.
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Sun, X., Wang, S., Shen, X. et al. Quasiunit regularity and QB-rings. Ukr Math J 64, 470–483 (2012). https://doi.org/10.1007/s11253-012-0659-4
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DOI: https://doi.org/10.1007/s11253-012-0659-4