has operator is missing from the operator precedence table

Section 5.1.1.9 defines operator precedence but doesn't mention the new "has" operator that can be used to determine if an enumeration value contains a particular member.

Enums only support equality and comparison operators, so it probably doesn't make a lot of difference.

If we add it to Primary then::

Not style has Sales.Pattern'Yellow'

would be interpreted the same as::

Not (style has Sales.Pattern'Yellow')