#! /usr/bin/env python
#
def l4_xor ( l1, l2 ):

#*****************************************************************************80
#
## L4_XOR returns the exclusive OR of two L4's.
#
#  Discussion:
#
#    An L4 is a logical value.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    21 November 2015
#
#  Author:
#
#   John Burkardt
#
#  Parameters:
#
#    Input, bool L1, L2, two values whose exclusive OR is needed.
#
#    Output, bool VALUE, the exclusive OR of L1 and L2.
#
  value =  ( (       l1   and ( not l2 ) ) or \
             ( ( not l1 ) and       l2   ) )

  return value

def l4_xor_test ( ):

#*****************************************************************************80
#
## L4_XOR_TEST tests L4_XOR. 
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    21 November 2015
#
#  Author:
#
#    John Burkardt
#
  print ( '' )
  print ( 'L4_XOR_TEST' )
  print ( '  L4_XOR computes the exclusive OR of two L4\'s' )
  print ( '' )
  print ( '      L1      L2  L4_XOR(L1,L2)' )
  print ( '' )

  for l1 in ( False, True ):
    for l2 in ( False, True ):
      l4 = l4_xor ( l1, l2 )
      print ( '   %5s   %5s    %5s' % ( l1, l2, l4 ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'L4_XOR_TEST' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  l4_xor_test ( )
  timestamp ( )