Notation: minimum for all (sub) elements

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Have an element list \Delta, these Elements have sub values, \alpha, \beta, \gamma. I want to write: the minimum from the sub element \alpha, over all elements \Delta.

How can I write this mathematically correct (in latex)?

\min ...

thx

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The key part is to just be clear about what you mean. Since it's not clear what exactly $\Delta$ consists of, suppose $\Delta$ is some arbitrary collection of elements $S$, where we use $S_\alpha$ to denote the $\alpha$-component of $S$. Then we could write

$$\min_{S\in\Delta}S_\alpha$$

to denote the minimum of all $\alpha$'s. Another approach (which I do not like as much, but still works), would be to define a function

$$\phi:\Delta\to\mathbb{R},\quad S\mapsto S_\alpha,$$

i.e. $\phi(S)$ is the $\alpha$-value of $S\in\Delta$. We could then write

$$\min_{S\in\Delta}\phi(S).$$

Of course there are other ways to do it as well; the most important part is to be clear.