We investigate functions f: I → ℝ (where I is an open interval) such that for all u,v ∈ I with u < v and f(u) ≠ f(v) and each c ∈ (min(f(u),f(v)),max(f(u),f(v))) there is a point w ∈ (u,v) such that f(w) = c and f is approximately continuous at w.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-cm117-1-6, author = {Zbigniew Grande}, title = {On a subclass of the family of Darboux functions}, journal = {Colloquium Mathematicae}, volume = {116}, year = {2009}, pages = {95-104}, zbl = {1177.26005}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm117-1-6} }
Zbigniew Grande. On a subclass of the family of Darboux functions. Colloquium Mathematicae, Tome 116 (2009) pp. 95-104. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-cm117-1-6/