The schema is valid, but if you have an instance like:

<root xmlns="ElemDecl/disallowedSubst">
  <Member1/>
</root>

Then you would get an error. And the error disappears if you remove the=

"block" attribute from the schema.

The "validly substitutable" rule is checked when the instance is valida=
ted,
and not when the schema is built.

Thanks,
Sandy Gao
XML Technologies, IBM Canada
Editor, W3C XML Schema WG
Member, W3C SML WG
(1-905) 413-3255 T/L 313-3255



                                                                       =
    
             Tobias Koenig                                             =
    
             <tobias.koenig@tr                                         =
    
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Hej,

today I have a question about the block attribute in conjunction with
substitution groups.

Let's assume the following schema
=========================
=================
<xsd:schema
  xmlns="ElemDecl/disallowedSubst"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  targetNamespace="ElemDecl/disallowedSubst"
  elementFormDefault="qualified"
  >

  <xsd:element name="root">
      <xsd:complexType>
          <xsd:sequence>
              <xsd:element ref="Head" maxOccurs="unbounded"/>
          </xsd:sequence>
      </xsd:complexType>
  </xsd:element>

  <xsd:element name="Head" type="Type"/>

  <xsd:complexType name="Type" block="restriction"/>

  <xsd:complexType name="derivedFromType">
      <xsd:complexContent>
          <xsd:restriction base="Type"/>
      </xsd:complexContent>
  </xsd:complexType>

  <xsd:element name="Member1" type="derivedFromType"
substitutionGroup="Head"/>

</xsd:schema>
=========================
==================
according to the test suite and some schema validators it is correct.

However I stumble about http://www.w3.org/TR/xmlschema11-1/#e-props-cor=
rect
4)
that defines
             For each member M of E.{substitution group affiliations},
E.{type definition}
             is =B7validly substitutable=B7 for M.{type definition}, su=
bject to
the blocking
             keywords in M.{substitution group exclusions}.

So when checking element Member1, derivedFromType must be validly
substitutable for Type, subject to the blocking keywords (empty set in =
this

case)

When checking =B7validly substitutable=B7, the first case (both are com=
plex
types)
is used, which means:
             derivedFromType is validly derived from Type subject to th=
e
blocking keywords
             in the union of {empty set} and {restriction}, as defined =
in
Type Derivation
             OK (Complex) (=A73.4.6.5)

Now when testing Type Derivation Ok (Complex) all rules from
http://www.w3.org/TR/xmlschema11-1/#cos-ct-derived-ok must be true, how=
ever
the first fails, as derivedFromType and Type are not the same type
but 'restriction' _is_ part of the constraint set.

Where is my error in reasoning? Any help is appreciated.

Ciao,
Tobias

=