  By analogy with the invariant Q-category defined by Scheerer, Stanley and
Tanr\'e, we introduce the notions of Q-sectional category and Q-topological
complexity. We establish several properties of these invariants. We also obtain
a formula for the behaviour of the sectional category with respect to a
fibration which generalizes the classical formulas for Lusternik-Schnirelmann
category and topological complexity.
