CCXML schema includes too restrictive regular expression

There is a regular expression restriction for ECMAScript left-hand-side expressions in the CCXML schema at http://www.w3.org/TR/2011/PR-ccxml-20110510/ccxml.xsd that excludes one of the expressions listed as example LHS expressions in the definition in section 3.4 of the PR.  That is, the regular expression

<xsd:pattern value="(([$\c]+)|([$\c]+\[[$\c]+\]))(\.(([$\c]+)|([$\c]+\[[$\c]+\])))*"/>

rules out the example

aaVar['arrayKey']

because it makes no provision for the string literal.