where $`p`$ is the pressure and $`\rho_{min} = 1440 `$, $`\rho_{max} = 1480 `$ and $`k = 5 \cdot 10^{-7} `$. Also, make sure the header is included in the `2pproblem.hh` file by uncommenting line 54. Furthermore, the new component has to be set as a liquid phase in the fluid system, i.e. comment line 98 and uncomment line 99. The density distribution of this phase (rhoN) at the final simulation time should look like this:

where $`p`$ is the pressure and $`\rho_{min} = 1440 `$, $`\rho_{max} = 1480 `$ and $`k = 5 \cdot 10^{-7} `$. Also, make sure the header is included in the `2pproblem.hh` file by uncommenting line 54. Furthermore, the new component has to be set as a liquid phase in the fluid system, i.e. comment line 101 and uncomment line 102. The density distribution of this phase (rhoN) at the final simulation time should look like this:

You can plot the density of the phase consisting of your compressible component by setting `PlotDensity` in `exercise-fluidsystem_a.input` to `true` and starting the simulation again.

Compare the gnuplot output to the following plot of the density function from above:

TODO

### 3. Implement a new fluid system

The problem file for this part of the exercise is `2p2cproblem.hh`. We now want to implement a new fluid system consisting of two liquid phases, which are water and the previously implemented compressible component. We will consider compositional effects, which is why we now have to derive our _TypeTag_ (`ExerciseFluidsystemTwoPTwoCTypeTag`) from a _TypeTag_ (`TwoPTwoC`) that holds the miscible two-phase