A subset is a portion of a set. Mathematically defining, a set in which all the elements can be found in another set is said to be a subset of the latter set.
http://answers.yahoo.com/question/index?qid=200806...

You could use the axiom of extensionality to make a simpler definition: $$A\subsetneq B =_\mathrm{def} (\forall x\in A. x\in B)\land \lnot(A=B).$$ This is, of course, equivalent to
http://math.stackexchange.com/questions/166651/wha...

According to the XMetal specs, you can style elements to look like tables using display:table;, etc. Read more here. So you could do this dl { display: table; } di{ display:tablerow
http://stackoverflow.com/questions/7416362/howcan...
