An Introduction to Some Spaces of Interval Functions
  The paper gives a brief account of the spaces of interval functions defined through the concepts of H-continuity, D-continuity and S-continuity. All three continuity concepts generalize the usual concept of continuity for real (point valued) functions. The properties of the functions in these new spaces are discussed and investigated, preserving essential properties of the usual continuous real functions being of primary interest. Various ways in which the spaces of H-continuous, D-continuous and S-continuous interval functions complement the spaces of continuous real functions are discussed. 
Roumen Anguelov