All my entries in the symbol index involving
$\|\cdot\|$ get rejected. For instance
How can I fix this?
Also note that
virtually duplicating the typeset component and index entry. Here's your MWE with a the above modifications:
Consider reading through Leslie Lamport's MakeIndex : An Index Processor For LaTeX.
Special characters for MakeIndex should be quoted: so to index
If you use more entries with
Call this file
This will disable the special feature of