<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>

.a { clip-path: url(z); }
#x { clip-path: inherit; }

</style>
</head>

<body>
    <div class="a">
        <div class="a" id="x"></div>
    </div>
    <script>
        getComputedStyle(document.getElementById("x"), "").clipPath;
    </script>
</body>

</html>