Invisible text on some slanted lines of a PDF
In the attached PDF, Silverman.83.pdf, some text is invisible when viewed with Okular, Xournal, Zathura, and Inkscape; and when converted with pdftocairo and pdftoppm. For example, the first part of the 7th line from the top is not visible. I cannot reproduce the problem with mupdf, Chromium, and Firefox, or when converting with ImageMagick.
Please let me know if there's any other details I could provide that would be helpful. I might be able to figure out how I made this PDF and provide steps to reproduce.