  The interior and exterior activities of bases of a matroid are well-known
notions that for instance permit one to define the Tutte polynomial. Recently,
we have discovered correspondences between the regions of gainic hyperplane
arrangements and coloredlabeled rooted trees. Here we define a general activity
theory that applies in particular to no-broken circuit (NBC) sets and labeled
colored trees. The special case of activity \textsf{0} was our motivating case.
As a consequence, in a gainic hyperplane arrangement the number of bounded
regions is equal to the number of the corresponding colored labeled rooted
trees of activity \textsf{0}.
