This question refers to microeconomic utility optimization where the utility function is Leontief. Are $\min(x_1,x_2)$ and $\min\{x_1,x_2\}$ interchangeable, or is there a difference?
edit: I interpret $\min(x_1,x_2)$ as the minimum of $x_1$ and $x_2$, i.e. if $x_1<x_2 \Rightarrow min(x_1,x_2) = x_1$ and $\min\{x_1,x_2\}$ is Leontief (complementary goods) which means that you need both goods to produce an output level $y$, thus even if $x_1<x_2$ you need both and $\min\{x_1,x_2\} \ne x_1$.