,,
\mathcal{L}=0,080 (../doc/src/manual/mov/wave_frames/frame_0080.png),085 (../doc/src/manual/mov/wave_frames/frame_0085.png)
a=b,090 (../doc/src/manual/mov/wave_frames/frame_0090.png),095 (../doc/src/manual/mov/wave_frames/frame_0095.png)
\nabla\cdot\bm{u} =0,100 (../doc/src/manual/mov/wave_frames/frame_0100.png),105 (../doc/src/manual/mov/wave_frames/frame_0105.png)
