Fix minor mistakes in the documentation.

dune/istl/bcrsmatrix.hh

@@ -1515,9 +1515,9 @@ namespace Dune {
       return *this;
     }
 
-    /*! \brief Substract the entries of another matrix to this one.
+    /*! \brief Subtract the entries of another matrix from this one.
      *
-     * \param b The matrix to add to this one. Its sparsity pattern
+     * \param b The matrix to subtract from this one. Its sparsity pattern
      * has to be subset of the sparsity pattern of this matrix.
      */
     BCRSMatrix& operator-= (const BCRSMatrix& b)

dune/istl/matrix.hh

@@ -220,7 +220,7 @@ namespace Dune {
       return (*this);
     }
 
-    /** \brief Multiplication with a scalar */
+    /** \brief Division by a scalar */
     Matrix<T>& operator/=(const field_type& scalar) {
       data_ /= scalar;
       return (*this);
@@ -242,7 +242,7 @@ namespace Dune {
 
     /*! \brief Subtract the entries of another matrix from this one.
      *
-     * \param b The matrix to add to this one. Its size has to
+     * \param b The matrix to subtract from this one. Its size has to
      * be the same as the size of this matrix.
      */
     Matrix& operator-= (const Matrix& b) {