Of course mathematicians would also consider brackets used like ]0,1[ and [0,1[ as valid notation for open or half-open intervals. And if you try hard enough yo

Of course mathematicians would also consider brackets used like ]0,1[ and [0,1[ as valid notation for open or half-open intervals. And if you try hard enough you can even make your braces {} look like a ξ and write some monstrosity like {ξ∈[0,1[}.