Let F be a subset of
**R**^{R}. The additivity of F, shortly add(F), is
the minimum cardinality of a subfamily
G of **R**^{R} with the
property that
h+G is a subset of F for no
h in **R**^{R}. In this paper we consider the notion of
super-additivity which we will denote by add*. If
F is a subset of **R**^{R}, then
add*(F) is the minimum cardinality of a family of functions G with the property
that for any subset H of
**R**^{R}
if |H| is less then
add(F), then there is a g in G
such that g+H is a subset of F. We calculate the super-additivities of the families
of Darboux-like functions and their complements.

**Last modified December 6, 2000.**