Something more.

git-svn-id: https://svn.dealii.org/trunk@28500 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/examples/step-20/step-20.cc b/deal.II/examples/step-20/step-20.cc
index 4bc9d5ef8ac7a046491a01f428964ac6ad574209..8131eed190247b59750156c861be579032b66b2a 100644 (file)
--- a/deal.II/examples/step-20/step-20.cc
+++ b/deal.II/examples/step-20/step-20.cc
@@ -615,7 +615,11 @@ namespace Step20
   // represents. As a consequence, in the code below, we also
   // implement a <tt>Tvmult</tt> function here that represents the
   // product of the transpose matrix with a vector. It is easy to see
-  // how this needs to be implemented here.
+  // how this needs to be implemented here. (Note, however, that even
+  // though we implement this function here, there will in fact not be
+  // any need for it as long as we use SolverCG as the solver since
+  // that solver does not ever call the function that provides this
+  // operation.)
   class ApproximateSchurComplement : public Subscriptor
   {
   public: