Issue in Selectors Module 4 grammar

Section 16.1 of the Selectors Level 4 WD (
http://www.w3.org/TR/selectors4/#grammar) defines the following rule:

  selector
    : compound_selector [ combinator simple_selector_sequence ]*
    ;


However no compound_selector rule exists. From context it looks like this
was a copy and partial update from Selectors Level 3 - was the intention to
rename the simple_selector_sequence rule to compound_selector?

Cheers,
    -Shane Stephens