How to do this double sum with a subscript in the middle?

Question

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I guess this is a duplicate: \mathop{\sum\sum}_{i<j} See https://tex.stackexchange.com/a/649824/4427 — egreg, May 18 '23 at 10:36

score 2 · Answer 1 · answered May 18 '23 at 10:42

2

Not finding a specific duplicate, I'll repeat the code used in https://tex.stackexchange.com/a/649824/4427

\documentclass{article}
\usepackage{amsmath}
\DeclareMathOperator{\cov}{cov}
\begin{document}
[
2\mathop{\sum\sum}{i<j} a{i}a_{j}\cdot \cov(X_{i}X_{j})
]
\end{document}

To be honest, I'd use a single summation sign.

answered May 18 '23 at 10:42

egreg

1,121,712

2

Excellent!. Thank you. – Eloy Ávalos May 18 '23 at 10:49

How to do this double sum with a subscript in the middle?

1 Answers1