A new marking strategy for the adaptive finite element approximation of optimal control constrained problems

We present a new marking strategy, named the conditional marking strategy, to be employed in the adaptive finite element approximation of distributed control constrained problems governed by second-order elliptic partial differential equations. The key feature of the conditional marking strategy is the possibility of dynamically choosing among separate marking strategies allowing the independent, possibly concurrent, reduction of different types of error. We assess the efficiency of this new strategy on several test problem