For a given function in some classes related to real derivatives, we examine the structure of the set of points which are not Lebesgue points. In particular, we prove that for a summable approximately continuous function, the non-Lebesgue set is a nowhere dense nullset of at most Borel class 4.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm100-1-9, author = {Don L. Hancock}, title = {The Borel structure of some non-Lebesgue sets}, journal = {Colloquium Mathematicae}, volume = {100}, year = {2004}, pages = {95-101}, zbl = {1069.26004}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm100-1-9} }
Don L. Hancock. The Borel structure of some non-Lebesgue sets. Colloquium Mathematicae, Tome 100 (2004) pp. 95-101. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm100-1-9/