“…The spirit of MinRes methods is to minimize the dual norm of the residual of the PDE given in variational form. Many strategies have been developed based on this idea over the last five decades, including the families of Galerkin Least-Squares methods [7,30,29], First Order Least-squares [12,13], residual minimization methods on dual discontinuous Galerkin norms [14,18,17,50,37], isogeometric residual minimization methods [15,39,38,40], and Discontinuous Petrov-Galerkin (DPG) methods [20,21,22,43,49]. As the residual operator lives in the dual of the test space and the dual norm is difficult to compute, the use of the Riesz representation theorem [45] is natural in this context.…”