Dear sir, I really appreciate that you did the tool of converting MathML to PDF, but when I tried to convert MathML to pdf found problem in the following: mml:math mml:mtr mml:mtd mml:mn1 mml:mtd mml:mn2 mml:mtr mml:mtd mml:mn3 mml:mtd mml:mn4 the column line and row line is vanished in pdf. I think you didn't insert this case. Thanks -- Muhammad Gad Production Developer Hindawi Publishing Corporation