Some selection theorems without convexity (Q1910025)

In [ibid. 156, 341-357 (1991; Zbl 0733.54011)], \textit{C. D. Horvath} recaptured the reviewer's selection theorem for convex set-valued functions [Ann. Math., II. Ser. 63, 361-382 (1956; Zbl 0071.15902)]\ in a more abstract, axiomatically defined context. The paper under review recaptures, in the same abstract context, certain more general selection theorems by the reviewer and \textit{C. Pixley} [Pac. J. Math. 87, 187-188 (1980; Zbl 0405.54015)]\ and by the reviewer [Fundam. Math. 111, 1-10 (1981; Zbl 0455.54012)].