SML Colouring Book

Take the following document, and colour it in according to Clark Evans' colouring syntax. 
<tag att="val">
<? A processing instruction ?>
<child>xxx</child>
<!-- Some comments -->
</tag>

Exercise One - SML syntax

<tag>
   <att>val</att>
   <pi>A processing instruction</pi>
   <child>xxx</child>
   <comment>Some comments</comment>
</tag>

Exercise Two - XML syntax

<tag att="val">
<? A processing instruction ?>
<child>xxx</child>
<!-- Some comments -->
</tag>

Exercise Three - SGML syntax

<tag val>
   <? A processing instruction ?>
   xxx
   <!-- Some comments -->
</tag>

Exercise Four - CSV (extra credit)

val,processing instruction,xxx,Some comments
N.B: I assume here that the 'tag' is the row, and therefore its colour can't be shown...?