About a year ago, I quit my PhD in mathematics. At the time, I was working on a project given to me by my former advisor. His contributions were as follows:
- Explaining the basic idea of the project, along with a few aspects of the problem that might cause difficulty
- Providing some papers on the subject that explain the background in more detail
- A few short (~10 minute) conversations regarding one or two details in those papers
- One half-hour conversation about a detail that neither of us could understand
Aside from these, I didn't receive any help on the parts of the proof that I finished before quitting. As far as I can tell, none of my former advisor, any of his students, or anyone else in the field has done any work towards completing the proof I was given.
Would it be inappropriate for me to finish the proof on my own, and submit it as a single-author paper?