corresponding `Makefile.in' files. This isn't so hard, just a matter
of editing in appropriate substitutions for the @...@ constructs.
-The `configure' script is built from `configure.ac' by the `autoconf'
-program. You need at least the version of autoconf specified in the
-AC_PREREQ(...) command to rebuild `configure' from `configure.ac'.
+The `configure' script is built from `configure.ac' by the
+`autogen.sh' script, which checks that `autoconf' and other build
+tools are sufficiently up to date and then runs the build tools.
BUILDING GNU EMACS BY HAND