latex problem using result obtained from Fricas integrate    
   sagemath 8.9.
I do not remember if I mentioned this before or not. I googled and did not find anything. If this is already mentioned and known issue, I am sorry and please feel free to close this.
Fricas returns  li in one result, which gets translated log_integral by sagemath. Which is OK. But the latex translation still uses log_integral. 
since in Latex, the _ is important , it looks bad when typeset.
I asked about this in the tex forum, and they say that using underscore in math names is not recommended.
So I think the translation of log_integral to latex should be changed to \li or \logintegral.  Then one can always make it a math operator using \DeclareMathOperator{\li}{log\_integral} but one can't do this, if the math name itself has _ in it. Latex gives an error.
In non-latex, it is ok to use log_integral.
Here is an example.
sage: var('t')
t
sage: result=integrate(1/log(t)^2,t, algorithm="fricas")
sage: result
(log(t)*log_integral(t) - t)/log(t)
sage: latex(result)
\frac{\log\left(t\right) log_integral\left(t\right) - t}{\log\left(t\right)}
 When compiling the above latex, it shows as
\documentclass[11pt]{article}
\usepackage{amsmath}
\begin{document}
$\frac{\log\left(t\right) log_integral\left(t\right) - t}{\log\left(t\right)}$
\end{document}
 
Using Fricas directly
(3) -> result:=integrate(1/log(t)^2,t)
        li(t)log(t) - t
   (3)  ---------------
             log(t)
                                         Type: Union(Expression(Integer),...)
(4) -> latex(result)                  
   (4)
  "{{{li \left( {t} \right)} \  {\log \left( {t} \right)}} -t} \over {\log \lef
  t( {t} \right)}"
                                                                 Type: String
(5) ->
 Compiling the above gives
\documentclass[11pt]{article}
\usepackage{amsmath}
\begin{document}
${{{li \left( {t} \right)} \  {\log \left( {t} \right)}} -t} \over {\log \left( {t} \right)}$
\end{document}
 
Not perfect either (since 'li should have been \li and made an operator) but it looks better that latex from sagemath,
Is this a known issue? Is there a workaround?
Thank you --Nasser
 
A quick workaround: