Merge pull request #6722 from bangerth/x-3

Avoid the use of unicode characters in comments.

Author: gassmoeller

include/aspect/mesh_deformation/fastscape.h

@@ -490,9 +490,9 @@ namespace aspect
         /**
          * Function of bedrock transport coefficient for hillslope diffusion.
          * Represents the parameter `kd` in the FastScape landscape evolution equation.
-         * Units: ${m²/yr}$ if "Use years instead of seconds in output" is true;
-         * otherwise, the units are ${m²/s}$. Then a time scale factor will be applied to
-         * convert it into  ${m²/yr}$ for Fastscape.
+         * Units: ${m^2/yr}$ if "Use years instead of seconds in output" is true;
+         * otherwise, the units are ${m^2/s}$. Then a time scale factor will be applied to
+         * convert it into  ${m^2/yr}$ for Fastscape.
          * This function is used only if `use_kd_distribution_function` is set to true.
          */
         Functions::ParsedFunction<2> kd_distribution_function;
@@ -504,18 +504,18 @@ namespace aspect
 
         /**
          * Constant bedrock transport coefficient value for hillslope diffusion
-         * Units: ${m²/yr}$ if "Use years instead of seconds in output" is true;
-         * otherwise, the units are ${m²/s}$. Then a time scale factor will be applied to
-         * convert it into  ${m²/yr}$ for Fastscape.
+         * Units: ${m^2/yr}$ if "Use years instead of seconds in output" is true;
+         * otherwise, the units are ${m^2/s}$. Then a time scale factor will be applied to
+         * convert it into  ${m^2/yr}$ for Fastscape.
          * This function is only used only if use_kf_distribution_function is false.
          */
         double constant_bedrock_transport_coefficient;
 
         /**
          * Sediment transport coefficient for hillslope diffusion.
-         * Units: ${m²/yr}$ if "Use years instead of seconds in output" is true;
-         * otherwise, the units are ${m²/s}$. Then a time scale factor will be applied to
-         * convert it into  ${m²/yr}$ for Fastscape.
+         * Units: ${m^2/yr}$ if "Use years instead of seconds in output" is true;
+         * otherwise, the units are ${m^2/s}$. Then a time scale factor will be applied to
+         * convert it into  ${m^2/yr}$ for Fastscape.
          * When set to -1 this is identical to the bedrock value.
          * (kd in FastScape surface equation applied to sediment).
          */