When both .fig and .pdf versions of a file are present, the .fig file (generated by xfig)
is the source file, and may be modified by xfig (or, if not available but the TransFig
package is available, by Inkscape.

To regenerate a pdf from a fig file, use TransFig's "fig2dev" command:

fig2dev -L pdf <fig_file> <out_file>

