ExpressionList = Expression { "," Expression } .
</pre>

<p>
If the type is present, all constants take the type specified, and
the expressions must be <a href="#Assignability">assignable</a> to that type,
which must not be a type parameter.
If the type is omitted, the constants take the
individual types of the corresponding expressions.
If the expression values are untyped <a href="#Constants">constants</a>,