$ cat a.f logical a,b,c a = .TRUE. b = .FALSE. c = a .xor.b print*,c end $ gfortran --version GNU Fortran (GCC) 4.3.0 20071217 (experimental) Copyright (C) 2007 Free Software Foundation, Inc.
GNU Fortran comes with NO WARRANTY, to the extent permitted by law. You may redistribute copies of GNU Fortran under the terms of the GNU General Public License. For more information about these matters, see the file named COPYING $ gfortran -c a.f a.f:4.17: c = a .xor.b 1 Error: Unknown operator 'xor' at (1) $ g77 a.f $ ./a.out T -- Summary: no .XOR. operator Product: gcc Version: 4.3.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bdavis at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34933