ParameterList  = ParameterDecl { "," ParameterDecl } .
ParameterDecl  = [ IdentifierList ] [ "..." ] Type .
</pre>

<p>
Within a list of parameters or results, the names (IdentifierList)
must either all be present or all be absent. If present, each name
stands for one item (parameter or result) of the specified type and
all non-<a href="#Blank_identifier">blank</a> names in the signature
must be <a href="#Uniqueness_of_identifiers">unique</a>.