Licensing confusion

[LourensVeen]

Hi! Thank you for sharing this code.

I have a question about its license. In the root of this repository is a LICENSE file containing the MIT license. However, in the Codes1.1 subdirectory, there is a README stating that the code is under a proprietary license.

As-is, I would interpret this to mean that the code in Codes1.1 is under that proprietary license, and that the code in Lebesgue2D and nudg++ (which perhaps you added later, and outside of your contract with the publisher?) is under the MIT license. Is that correct? Or was the code relicensed, and is it all under the MIT license now?

It would be good if you could make explicit who owns the copyright to what, and what license they offer it under.