message: Listing MixedBilinearForm::FormRectangularLinearSystem as virtual
diff: @@ -876,10 +876,11 @@ public:
  Return in @a A a *reference* to the system matrix that is column-constrained.
  The reference will be invalidated when SetOperatorType(), Update(), or the
  destructor is called. */
  - void FormRectangularLinearSystem(const Array<int> &trial_tdof_list,
  + virtual void FormRectangularLinearSystem(const Array<int> &trial_tdof_list,
  const Array<int> &test_tdof_list,
  Vector &x, Vector &b,
  - OperatorHandle &A, Vector &X, Vector &B);
  + OperatorHandle &A, Vector &X,
  + Vector &B);
  /** @brief Form the linear system A X = B, corresponding to this bilinear
  form and the linear form @a b(.).
  