I was wondering about an efficient way to generate an inner product symbol like
\[ \langle\langle u, v \rangle\rangle \]
(i.e., double angle brackets), or a norm symbol like
\[ \lvert\lVert x \rVert\rvert \]
(i.e., triple bars). Of course, the above examples are terrible, no respect for spaces. Is there an efficient way of doing this so that the delimiters are extensible (compatible with
I know of the package nath, but it's quite incompatible with amsmath, and generates thousands of errors, so is not an option. I've also tried with "DeclareMathDelimiterX" in mathmode, but couldn't get it to work quite as well as I'ld like.