<!DOCTYPE html>
<link rel=author href="mailto:jarhar@chromium.org">
<link rel=help href="https://github.com/w3c/csswg-drafts/issues/6429">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/css/support/interpolation-testcommon.js"></script>

<body>
<script>
const alwaysVisible = [
  {at: -1, expect: 'visible'},
  {at: 0, expect: 'visible'},
  {at: 0.1, expect: 'visible'},
  {at: 0.9, expect: 'visible'},
  {at: 1, expect: 'visible'},
  {at: