# Non-intrusive super/subscripts using slanted Greek with tensor?

I was quite happy with how the tensor package is able to typeset beautiful tensor expressions … until I decided to use the ISO convention for my Christoffel symbols.

\documentclass{article}
\usepackage{newtxtext}
\usepackage[slantedGreek]{newtxmath}
\usepackage{tensor}
\usepackage{mathtools}% for cases*'
\begin{document}
$\begin{cases*} \upGamma\indices{^\mu_{\sigma\rho}} & \TeX\ convention \\ \Gamma\indices{^\mu_{\sigma\rho}} & ISO convention \\ \Gamma{}^\mu_{\phantom{\mu}\sigma\rho} & Ad hoc attempt \end{cases*}$
\end{document}


As shown in the picture, direct use of \indices leads to “intrusive” \sigma into the space under \mu (or, “intrusive” \mu into the space above \sigma), which is understandably caused by the slanted \Gamma.

This problem is much more visible when I use MathTime Pro 2 as my math font:

When switching from the TeX convention to the ISO convention, I’d like my tensor super/subscripts to be non-intrusive. Is there anything I can do/modify so I don’t have to manually change every \indices using the “ad hoc” approach?

• You can just put an empty group after \gamma and before \indices: \Gamma{}\indices{^\mu_{\sigma\rho}}`. – campa Aug 16 '18 at 7:15
• @campa -- this seems worth an answer, just to keep the question from being unanswered, – barbara beeton Oct 19 '18 at 16:31
• @barbarabeeton Uh, I'd forgotten this one. However, I'm not sure what the package is doing and I don't really like writing answers which just work without me knowing why. I'll think about it in the weekend, if you don't mind... – campa Oct 19 '18 at 16:50