*plus* normal direction):
In DG methods we have to evaluate fluxes over element faces.
-Exemplarily for an upwind like flux $u^*(\mathbf{x}) = u^+(\mathbf{x})$ over element face $\partial K$ we have to compute
+Exemplarily for an upwind-like flux $u^*(\mathbf{x}) = u^+(\mathbf{x})$
+over element face $\partial K$ we have to compute
@f[
F^{\partial K} = \left(\varphi^-, u^+\right)_{\partial K} \approx \sum_q \varphi^-(\mathbf{x}_q^{\partial K})\ u^+(\mathbf{x}_q^{\partial K})\ w_q^{\partial K} |J_q|^{\partial K}.
@f]
`FEFaceEvaluation::gather_evaluate(src, EvaluationFlags::values)` and `FEFaceEvaluation::get_value(q)` extract
the value at quadrature point $\mathbf{x}_q^{\partial K}$ from `src`. `FEFaceEvaluation::submit_value(value, q)`
-multiplies the value with the quadrature weight and the Jacobi determinant at $\mathbf{x}_q^{\partial K}$.
-Eventually `FEFaceEvaluation::integrate_scatter(EvaluationFlags::values, dst)` tests all submitted values by the
-basis function and writes the result to `dst`. The corresponding code reads
+multiplies the value with the quadrature weight and the Jacobian determinant at $\mathbf{x}_q^{\partial K}$.
+Eventually `FEFaceEvaluation::integrate_scatter(EvaluationFlags::values, dst)` multiplies the values
+queued for evaluation by `FEFaceEvaluation::submit_value()` by the value of the
+basis functions and writes the result to `dst`. The corresponding code reads
@code
const auto face_function =