11.4 Environment variables
There are 3 environment variables used by the Coq system.
$COQBIN for the directory where the binaries are,
$COQLIB for the directory whrer the standard library is, and
$COQTOP for the directory of the sources. The latter is useful
only for developpers that are writing there own tactics using
do_Makeffile (see 12.3). If $COQBIN or
$COQLIB are not defined, Coq will use the default values
(choosen at installation time). So these variables are useful onlt if
you move the Coq binaries and library after installation.