Online PHP editor | refs for mJZKd

<?php $f= fn($a)=>preg_replace('/\d+/','^{$0}',normalizer_normalize("\\$$a\\$",8)); echo $f('x')."\n"; echo $f('xyz')."\n"; echo $f('x²')."\n"; echo $f('x²¹')."\n"; echo $f('x²yz²')."\n"; echo $f('xy¹¹z')."\n"; echo $f('x⁴')."\n"; echo $f('x⁶⁰')."\n";