If I have an expression like $$ \mu^i(x,t) = 0 \qquad, \qquad \qquad i=1,\dots, K $$
I want a more compact way of specifying that the index $i$ takes integer values from $1$ to $K$. I'm looking for something like $i\in I_1^K$, or $i\in \mathbb{Z}_1^K$, etc. Is there a standard notation for this that I have missed? Something like $i\in [1,K]$ does not work as it does not make clear that $i$ is an integer.