The macros defined by the commath package are not accessible with
TeX-insert-macro.
The package is included via \usepackgage and compilation of a file with
commath works. The commath macros are not in TeX-symbol-list. Even
though debug mode is enabled, no error is thrown.

Expected behavior:
C-c <RET> od
should produce \od{}{}

Actual behavior:
C-C <RET> od
produces: \od

Reproducible: always

Minimal sample:

\documentclass{article}

\usepackage{commath}

\begin{document}
\begin{equation}
\od{f}{x}
\end{equation}

\end{document}


Emacs  : GNU Emacs 24.5.1 (x86_64-redhat-linux-gnu, GTK+ Version 3.18.9)
  of 2016-04-11 on buildvm-25.phx2.fedoraproject.org
Package: 11.89

current state:
==============
(setq
  AUCTeX-date "2015-11-13"
  window-system 'x
  LaTeX-version "2e"
  TeX-style-path '("/var/auctex" "/usr/share/emacs/site-lisp/auctex/style"
           "/home/ash1125/.emacs.d/auctex/auto"
           "/home/ash1125/.emacs.d/auctex/style" "auto" "style")
  TeX-auto-save nil
  TeX-parse-self nil
  TeX-master t
  TeX-command-list '(("TeX"
              "%(PDF)%(tex) %(file-line-error) %(extraopts) 
%`%S%(PDFout)%(mode)%' %t"
              TeX-run-TeX nil
              (plain-tex-mode ams-tex-mode texinfo-mode) :help
              "Run plain TeX")
             ("LaTeX" "%`%l%(mode)%' %t" TeX-run-TeX nil
              (latex-mode doctex-mode) :help "Run LaTeX")
             ("Makeinfo" "makeinfo %(extraopts) %t" TeX-run-compile nil
              (texinfo-mode) :help "Run Makeinfo with Info output")
             ("Makeinfo HTML" "makeinfo %(extraopts) --html %t"
              TeX-run-compile nil (texinfo-mode) :help
              "Run Makeinfo with HTML output")
             ("AmSTeX" "amstex %(PDFout) %(extraopts) %`%S%(mode)%' %t"
              TeX-run-TeX nil (ams-tex-mode) :help "Run AMSTeX")
             ("ConTeXt"
              "%(cntxcom) --once --texutil %(extraopts) %(execopts)%t"
              TeX-run-TeX nil (context-mode) :help "Run ConTeXt once")
             ("ConTeXt Full" "%(cntxcom) %(extraopts) %(execopts)%t"
              TeX-run-TeX nil (context-mode) :help
              "Run ConTeXt until completion")
             ("BibTeX" "bibtex %s" TeX-run-BibTeX nil t :help
              "Run BibTeX")
             ("Biber" "biber %s" TeX-run-Biber nil t :help "Run Biber")
             ("View" "%V" TeX-run-discard-or-function t t :help
              "Run Viewer")
             ("Print" "%p" TeX-run-command t t :help "Print the file")
             ("Queue" "%q" TeX-run-background nil t :help
              "View the printer queue" :visible TeX-queue-command)
             ("File" "%(o?)dvips %d -o %f " TeX-run-dvips t t :help
              "Generate PostScript file")
             ("Dvips" "%(o?)dvips %d -o %f " TeX-run-dvips nil t :help
              "Convert DVI file to PostScript")
             ("Dvipdfmx" "dvipdfmx %d" TeX-run-dvipdfmx nil t :help
              "Convert DVI file to PDF with dvipdfmx")
             ("Ps2pdf" "ps2pdf %f" TeX-run-ps2pdf nil t :help
              "Convert PostScript file to PDF")
             ("Index" "makeindex %s" TeX-run-index nil t :help
              "Run makeindex to create index file")
             ("Xindy" "texindy %s" TeX-run-command nil t :help
              "Run xindy to create index file")
             ("Check" "lacheck %s" TeX-run-compile nil (latex-mode)
              :help "Check LaTeX file for correctness")
             ("ChkTeX" "chktex -v6 %s" TeX-run-compile nil (latex-mode)
              :help "Check LaTeX file for common mistakes")
             ("Spell" "(TeX-ispell-document \"\")" TeX-run-function nil
              t :help "Spell-check the document")
             ("Clean" "TeX-clean" TeX-run-function nil t :help
              "Delete generated intermediate files")
             ("Clean All" "(TeX-clean t)" TeX-run-function nil t :help
              "Delete generated intermediate and output files")
             ("Other" "" TeX-run-command t t :help
              "Run an arbitrary command")
             )