Precision problem with matrix inversion

[parisse]

I did not check with a CAS numeric matrix, because you did not paste it in algebraic format. As a general rule, if you think you have found a bug, please report it with a textual input that everyone can copy/paste to the emulator, not just as a screen capture. It will cost you more time, but it will save every tester that time, that's much more efficient! Thank you.