| <!-- This only draws the <div> elements since the math element should be |
| hidden by the red boxes. --> |
| <div style="height: 3em; width: 10em;"> |
| <div style="position: absolute; left: 0; width: 10em; height: 3em; |
| <div style="position: absolute; left: 0; width: 2em; height: 3em; |
| <!-- This only draws the <div> elements since the math element should be |
| hidden by the red boxes. --> |
| <div style="height: 3em; width: 10em;"> |
| <div style="position: absolute; left: 0; width: 10em; height: 3em; |
| <div style="position: absolute; left: 4em; width: 2em; height: 3em; |
| <!-- This only draws the black <div> covering the math element. --> |
| <div style="height: 3em; width: 10em;"> |
| <div style="position: absolute; left: 0; width: 10em; |
| <span style="font-size: 1.5em;">X</span> |
| <!-- This only draws the black <div> covering the math element. --> |
| <div style="height: 5em; width: 10em;"> |
| <div style="position: absolute; left: 0; width: 10em;"> |
| <div style="position: absolute; left: 0; top: 2em; |
| width: 10em; background: black;"> |
| <span style="font-size: 1.5em;">X</span> |