# What is the following tooltip when I hover on it?

Here is an screenshot from J. M. Lee book (Riemannian manifolds 2018) (page 15):

(I think) It has been defined by

\font\ursymbol=psyr at 12pt
\def\urpartial{\mbox{\ursymbol\char"B6}}


But when I hover on it (inside the green box that I have drawed) a tooltip appear as shown in above!! what is the wrong? Notice that there are some similar formulas but without inverse sign in the book but without this tooltip!!

• presumably the author put some bad markup into the file making an accidental tooltip, without the sources how can anyone guess, reporting it to the publisher would seem better than just asking a general question here. – David Carlisle Nov 3 '19 at 15:36
• I just want to know it is because of Latex or final designing by other softwares? – C.F.G Nov 3 '19 at 15:39
• how can anyone tell that? Given the screenshot it's impossible to know if tex was used at all. – David Carlisle Nov 3 '19 at 15:39
• I have no idea what that is or how it got there. It's not coded in my LaTeX file, and it wasn't in the PDF I sent the publisher. It also wasn't noted in the list of changes I got back from the publisher after proofreading. It seems to have first shown up in one of the PDF proof copies they sent me, but I never noticed it. – Jack Lee Nov 4 '19 at 16:16