Maybe this? with a little help from `\mathclap`

and `stackengine`

. EDIT to replace `\ldots`

with `\dots`

and `\cdots`

, per Mico's request. I hope I interpreted his request in the right way...

```
\documentclass{article}
\usepackage{amsmath}
\usepackage{mathtools}
\usepackage{stackengine}
\stackMath
\begin{document}
$\displaystyle x \wedge y =\qquad
\sum_{\mathclap{1 \leq i_1 < \dots < i_p \leq n}}\quad
\sum_{\stackunder[5pt]{}{\scriptstyle\mathclap{1 \leq j_1 < \dots < j_q \leq n}}}
a_{i_1 \dots i_p} b_{j_1 \dots j_q}
\; \underbrace{e_{i_1} \wedge \cdots \wedge e_{i_p} \wedge e_{j_1} \wedge \cdots \wedge e_{j_q}}_{\text{is sometimes 0}}$
\end{document}
```

Another solution, also provided by the `mathtools`

package, is to use its `\smashoperator`

macro. In fact, by writing `\smashoperator[r]{...}`

, one can arrange that the material overlaps only on the right, rather than on both sides. (Observe that the word "Note" does not overlap with the material below the summation sign.)

Note that I would also create a macro, called (say) `\VaR`

, to typeset the string `VaR`

with upright letters. And, do note that there's no point in encasing `P(X)\cdot x`

in curly braces.

```
\documentclass{article}
\usepackage{mathtools}
\newcommand\VaR{\mathrm{VaR}}
\begin{document}
\begin{equation}
\text{Note:}\smashoperator[r]{\sum_{X\leq\VaR_\alpha(X)}} P(X)\cdot x
\end{equation}
\end{document}
```

*Addendum to address the OP's follow-up question*: You may achieve your typesetting objective by (a) switching to the basic, i.e., centered version of the `\smashoperator`

directive and inserting a suitable "kern" at the start of the subscript material. I know it's not fruitful to argue about tastes, but in my opinion the result of right-shifting the subscript material is anything but good-looking.

```
\documentclass{article}
\usepackage{mathtools}
\newcommand\VaR{\mathrm{VaR}}
\begin{document}
\[
\text{Note:}\smashoperator{\sum_{\mkern70mu X\leq\VaR_\alpha(X)}} P(X)\cdot x
\]
\end{document}
```

## Best Answer

Something like:

`\mathop{\sum_{j=1}^{\infty}\sum_{k=1}^{\infty}}_{j>k}`

maybe?

Looks like this:

Or if you want it on the same line as j=1 and k=1, then maybe:

`\mathop{\sum^{\infty}\sum^{\infty}}_{j=1\ j>k\ k=1}`