preprocessor.php

<?

private function removeDuplicates(
    array $patternsWithPossibleDuplicates): array {
    return array_intersect_key(
        $patternsWithPossibleDuplicates,
        array_unique(
            array_map("strtolower", $patternsWithPossibleDuplicates)));
}

function simplify(array $patterns): array {
    $patternsWithoutDuplicates = $this->removeDuplicates($patterns);
    return array_values(array_filter($patternsWithoutDuplicates,
        fn ($outerPattern) => 
           $this->alreadyIncludesPattern(
               $patternsWithoutDuplicates, $outerPattern)));
}