atan               25 maint/gnulib/lib/atanf.c   return (float) atan ((double) x);
atan               26 maint/gnulib/lib/atanl.c   return atan (x);
atan               24 maint/gnulib/tests/test-atan.c SIGNATURE_CHECK (atan, double, (double));
atan               36 maint/gnulib/tests/test-atan.c   y = atan (x);