Generalized
-piecewise functions constructed from given monotone path-connected boundedly compact subsets of the space
are studied. They are shown to be monotone path-connected suns. In finite-dimensional polyhedral spaces, luminosity points of sets admitting a lower semicontinuous selection of the metric projection operator are investigated. An example of a non-
-connected sun in a four-dimensional polyhedral normed space is constructed.
Bibliography: 14 titles.