[selectors4] An+B nits

In the An+B micro syntax section [1], I noted the following issues:

• Example 35 uses '-n', but only later is it explained that an 'n' without a number before it is the same as 1n (thus '-n' means the same as '-1n'). For example 35, it would be more clear at that point if it was written as '-1n+6'. It would also be helpful IMO if there was also an example there using a negative n that resulted in a list of more than one item, such as:
–4n+10   /* represents the 6th and 2nd elements in the list */
By the way, would that be the right order of the results in the CSSOM, or do they get sorted?

• the spec says that a negative 'n' is allowed, but it does not make it clear how to write that. The text above examples 38 and 39 imply that the minus sign can just replace the plus sign, but I think there should be prose to that effect, such as in the opening paragraph of the syntax section. Is it valid to also add a negative, as in '5n + -1'? I think the grammar section says no, but I am not sure.



1) http://dev.w3.org/csswg/selectors4/#anb