Issue pointed out by Jean Ragusa: Properly parenthesize a formula.

git-svn-id: https://svn.dealii.org/trunk@32103 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/examples/step-40/doc/results.dox b/deal.II/examples/step-40/doc/results.dox
index 8b62cec1e753fbd89afc9b552d268b919d554b74..45eec441e835f5cd0ef484ce3367d926659ade5f 100644 (file)
--- a/deal.II/examples/step-40/doc/results.dox
+++ b/deal.II/examples/step-40/doc/results.dox
@@ -129,7 +129,7 @@ multigrid method from the <a
 href="http://acts.nersc.gov/hypre/" target="_top">Hypre package</a> as
 a preconditioner, which unfortunately uses signed 32-bit integers to
 index the elements of a %distributed matrix. This limits the size of
-problems to $2^31-1=2,147,483,647$ degrees of freedom. From the graphs
+problems to $2^{31}-1=2,147,483,647$ degrees of freedom. From the graphs
 above it is obvious that the scalability would extend beyond this
 number, and one could expect that given more than the 4,096 machines
 shown above would also further reduce the compute time. That said, one