flip at 1? yes
flop at 1? yes      -> Would return false, but must return true once.
flip at 2? yes
flop at 2? yes      -> Would return false, but must return true once.
flip at 2? yes
flop at 2? yes      -> Would return false, but must return true once.
flip at 2? yes
flop at 2? yes      -> Would return false, but must return true once.
flip at 2? yes
flop at 2? yes      -> Would return false, but must return true once.

##</code><code>##

my $x=1;
my $y=0;
for(1,2,3,4,5) 
{
  next  if (printf("flip at %s? %s\n",$_,$x?'yes':'no'),$x)
        .. (printf("flop at %s? %s\n",$_,$y?'yes':'no'),$y);
  print "$_\n";
}

##</code><code>##

flip at 1? yes
flop at 1? no      -> Returns true.
flop at 2? no      -> Returns true.
flop at 3? no      -> Returns true.
flop at 4? no      -> Returns true.
flop at 5? no      -> Returns true.