In my diploma thesis I need to LaTeX a concatenation over a set of sets.

I use the `\cdot`

symbol for concatenation of two sets as in `A \cdot B`

. (Please correct me if this is a wrong symbol for concatenation).

I would need to type a concatenation over a set of sets, using a `\bigcdot`

symbol or an equivalent one.

It should be like when you use the `\bigcup`

symbol to do a union over a set of sets, as in `\bigcup_{i=1}^n A_{i}`

.

My LaTeX installation, however, does not know about such a symbol and I haven't found a clue on Google search either.

## Best Answer

Besides what has been said in this post. You can also define a new "bigcdot" operator using

`scalerel`

package, for example:gives you:

EDIT:I considered some alternative solutions so I will post them here.

As one can see, a problem with the

`scalerel`

solution is that it stretch the`\cdot`

too wide such that the symbol become less appeal (at least to me). So how do we get a smaller dot with bigger "size"? For instance, let's say we want to have the dot in`\bigodot`

(we can use`\boldsymbol{\cdot}`

for the dot only) without the circle, how do we do it?Well, there are at least two ways: first, we want to declare this new symbol as a math operator, such that superscript and subscript will go directly above and below it, then we either enclose the bold cdot with a box of total height of

`\bigodot`

, or we insert a invisible character of the size of`\bigodot`

after the bold cdot, as illustrate by the code (both do not need any package other than`amsmath`

):and

That said, we can also redefine other "small" symbol, such as

`\bullet`

and`\|`

, in similar ways. In the end, let's compare the results: