While running Kerr_Schild.ipynb
(https://github.com/egourgoulhon/BHLectures/blob/master/sage/Kerr_Schild.ipynb)
I get a bad output; not necessarily incorrect. I copyed the Tex to an Latex gui editor and it looks right.
When the last expression is evaluated it outputs Tex instead of Latex image. It is very long so it might just be a converter problem; that I can ignore. After the leadin the expression:
```
g.riemann().display()
``` Well I can't attach a trimmed file but I can provide a dropbox link if needed. The above expression was added just after the "Kerr Metric" paragraph; about line 13. Is this my machine or Latex or Jupyter ?
