$AE = [Ä {A \u0308}];
$OE = [Ö {O \u0308}];
$UE = [Ü {U \u0308}];

[ä {a \u0308}] → ae;
[ö {o \u0308}] → oe;
[ü {u \u0308}] → ue;

{$AE} [:Lowercase:] → Ae;
{$OE} [:Lowercase:] → Oe;
{$UE} [:Lowercase:] → Ue;

$AE → AE;
$OE → OE;
$UE → UE;

::Any-ASCII;
