Correct an incomplete latex command in math mode

diff --git a/include/deal.II/differentiation/sd/symengine_math.h b/include/deal.II/differentiation/sd/symengine_math.h
index 1a73bed06a4193d6ea11d1f8969c8cd2504020ac..a4c17380144761d4a1939955355c410f004e1067 100644 (file)
--- a/include/deal.II/differentiation/sd/symengine_math.h
+++ b/include/deal.II/differentiation/sd/symengine_math.h
@@ -117,7 +117,7 @@ namespace Differentiation
 
     /**
      * Return a symbolic number that represents the Euler constant
-     * $e approx 2.71828$ raised to the given @p exponent.
+     * $e \approx 2.71828$ raised to the given @p exponent.
      *
      * Mimics the function <code> std::exp(exponent) </code> using the standard
      * math library.