int main ( void )
{
  int x = 0, y = 1, z = 2;

  if ( ( x == 1 ) || ( y == 2 ) )  //遵循1
  {
    z = 3;
  }

  if ( ( x == 3 ) && ( y == 4 ) )  //遵循2
  {
    z = 5;
  }

  return ( 0 );
}