| <html xmlns="http://www.w3.org/1999/xhtml"> | |
| <body> | |
| <div><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> | |
| <mtable> | |
| <mtr> | |
| <mtd><mi>x</mi></mtd> | |
| <mtd rowspan="4" columnspan="4"><mi>y</mi></mtd> | |
| </mtr> | |
| <mtr> | |
| <mtd rowspan="0" columnspan="0"><mi>z</mi></mtd> | |
| <mtd><mi>w</mi></mtd> | |
| </mtr> | |
| </mtable> | |
| </math></div> | |
| </body> | |
| </html> |