A professor has only proofread my paper. Should I include him as author? I am currently working on a paper in Computer Science. I am the sole author of the paper. Every aspect of the paper, the idea, the implementation, figures, plots, results are all solely based on my efforts. Since I wanted it to be accepted into a good conference/journal, I wanted it proofread. I approached a professor who is doing research somewhere close the same field (not exactly the same field) as my paper's. He made corrections to the paper based on semantics and visual aesthetics. Should I include him as a secondary author? Is it ethically wrong if I just mention him in the acknowledgements section? How should I go about dealing with this situation?
I would thank him in the acknowledgments. Although there is no set standard for what is required to be an author, it is generally accepted that they must make a research contribution. Proofreading definitely doesn't meet that criterion (or any of the other criteria that I have seen).

I did this in one of my recent papers. I just said: 


  We would also like to thank Bob Bob for his helpful feedback on a draft of the paper.