Published online by Cambridge University Press: 09 April 2009
The present paper on functions of bounded variation relative to a set has its point of departure in the work of R. L. Jeffery [10]. Below we recapitulate Jeffery's class U of functions of bounded variation relative to a set, we state and prove a number of preliminary lemmas and theorems, we introduce a suitable pseudo- metric space (X, d) of such functions, and the analogous space , and prove that (X, d) is separable, that every closed sphere in (X, d) is compact and that is complete. These results extend known results of C. R. Adams, and C. R. Adams and A. P. Morse for the space of usual BV functions.