[PL] Fix various typos in doxygen formulae.

ProcessLib/HydroMechanics/HydroMechanicsFEM.h

@@ -352,7 +352,7 @@ private:
      * @param dxdot_dx        Value of \f$\dot{x} \cdot dx\f$.
      * @param dx_dx           Value of \f$ x \cdot dx\f$.
      * @param local_M_data    Mass matrix of an element, which takes the form of
-     *                        \f$ \inta N^T N\mathrm{d}\Omega\f$. Not used.
+     *                        \f$ \int N^T N\mathrm{d}\Omega\f$. Not used.
      * @param local_K_data    Laplacian matrix of an element, which takes the
      *         form of \f$ \int (\nabla N)^T K \nabla N\mathrm{d}\Omega\f$.
      *                        Not used.
@@ -387,7 +387,7 @@ private:
      * @param dxdot_dx        Value of \f$\dot{x} \cdot dx\f$.
      * @param dx_dx           Value of \f$ x \cdot dx\f$.
      * @param local_M_data    Mass matrix of an element, which takes the form of
-     *                        \f$ \inta N^T N\mathrm{d}\Omega\f$. Not used.
+     *                        \f$ \int N^T N\mathrm{d}\Omega\f$. Not used.
      * @param local_K_data    Laplacian matrix of an element, which takes the
      *         form of \f$ \int (\nabla N)^T K \nabla N\mathrm{d}\Omega\f$.
      *                        Not used.

ProcessLib/RichardsMechanics/RichardsMechanicsFEM.h

@@ -157,7 +157,7 @@ private:
      * @param dxdot_dx        Value of \f$\dot{x} \cdot dx\f$.
      * @param dx_dx           Value of \f$ x \cdot dx\f$.
      * @param local_M_data    Mass matrix of an element, which takes the form of
-     *                        \f$ \inta N^T N\mathrm{d}\Omega\f$. Not used.
+     *                        \f$ \int N^T N\mathrm{d}\Omega\f$. Not used.
      * @param local_K_data    Laplacian matrix of an element, which takes the
      *         form of \f$ \int (\nabla N)^T K \nabla N\mathrm{d}\Omega\f$.
      *                        Not used.
@@ -192,7 +192,7 @@ private:
      * @param dxdot_dx        Value of \f$\dot{x} \cdot dx\f$.
      * @param dx_dx           Value of \f$ x \cdot dx\f$.
      * @param local_M_data    Mass matrix of an element, which takes the form of
-     *                        \f$ \inta N^T N\mathrm{d}\Omega\f$. Not used.
+     *                        \f$ \int N^T N\mathrm{d}\Omega\f$. Not used.
      * @param local_K_data    Laplacian matrix of an element, which takes the
      *         form of \f$ \int (\nabla N)^T K \nabla N\mathrm{d}\Omega\f$.
      *                        Not used.

ProcessLib/ThermoMechanicalPhaseField/ThermoMechanicalPhaseFieldProcess.h

@@ -42,7 +42,7 @@ struct ThermoMechanicalPhaseFieldLocalAssemblerInterface;
  *       &\varrho:&              \mbox{density,}\\
  *       &g_\mathrm{c}:&         \mbox{fracture energy,}\\
  *       &\varepsilon:&          \mbox{length scale}\\
- *       &\c_\mathrm{p}:&        \mbox{specific heat capacity in constant
+ *       &c_\mathrm{p}:&        \mbox{specific heat capacity in constant
  * pressure}\\
  *       &\kappa_\mathrm{eff}:&  \mbox{effectiev thermal conductivity}\\
  *    \f}