My pull request solution strips out orphan curly braces, while leaving matching curly braces in place. Users should use \leftbrace or \rightbrace in markup instead, as per this advice: http://tex.stackexchange.com/a/109066
https://github.com/kovidgoyal/calibre/pull/125
My pull request solution strips out orphan curly braces, while leaving matching curly braces in place. Users should use \leftbrace or \rightbrace in markup instead, as per this advice: http:// tex.stackexchan ge.com/ a/109066
https:/ /github. com/kovidgoyal/ calibre/ pull/125