equals(box.width, 500, epsilon, "width");
            assert_approx_equals(box.height, 400, epsilon, "height");
        }, `width and height properties on ${tag}`);

        test(function() {
            assert_true(MathMLFeatureDetection[`has_${tag}`](), `${tag} is supported`);
            var style = `inline-size: 600px; block-size: 700px;`;
            element.setAttribute("style", style);
            let box = element.getBoundingClientRect();
            assert_approx_equals(box.width, 600, epsilon, "wi