Function: reftex-isearch-minor-mode

When on, isearch searches the whole document, not only the current file.
This minor mode allows isearch to search through all the files of
the current TeX document.

With no argument, this command toggles
`reftex-isearch-minor-mode'. With a prefix argument ARG, turn
`reftex-isearch-minor-mode' on if ARG is positive, otherwise turn it off. (fn &optional ARG)