changing the reference for saddle point problem; fixed bug in E(u)

git-svn-id: https://svn.dealii.org/trunk@26001 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/examples/step-41/doc/intro.dox b/deal.II/examples/step-41/doc/intro.dox
index 42dec00a16644118ff3502353b6e77d54d00ff56..360833e05df2ad366957d09917af8bafbe7c6699 100644 (file)
--- a/deal.II/examples/step-41/doc/intro.dox
+++ b/deal.II/examples/step-41/doc/intro.dox
@@ -91,7 +91,7 @@ obstacle).
 
 An obvious way to obtain the variational formulation of the obstacle problem is to consider the total potential energy:
 @f{equation*}
- E(u):=\dfrac{1}{2}\int\limits_{\Omega} \nabla u \cdot \nabla - \int\limits_{\Omega} fu.
+ E(u):=\dfrac{1}{2}\int\limits_{\Omega} \nabla u \cdot \nabla u - \int\limits_{\Omega} fu.
 @f}
 We have to find a solution $u\in G$ of the following minimization problem:
 @f{equation*}
@@ -165,9 +165,8 @@ statement above only appears to have the wrong sign because we have
 $\mu-\lambda<0$ at points where $\lambda=0$, given the definition of $K$.
 
 The existence and uniqueness of $(u,\lambda)\in V\times K$ of this saddle
-point problem has been stated in Grossmann and Roos: Numerical treatment of
-partial differential equations, Springer-Verlag, Heidelberg-Berlin, 2007, 596
-pages, ISBN 978-3-540-71582-5.
+point problem has been stated in Glowinski, Lions and Tr\'{e}moli\`{e}res: Numerical Analysis of Variational
+Inequalities, North-Holland, 1981.