<xs:element name="and" type="Elementary-functions.type"/>
<xs:element name="or" type="Logic.type"/>
<xs:element name="xor" type="Logic.type"/>
<xs:element name="not" type="Logic.type"/>
<xs:element name="exists" type="Logic.type"/>
<xs:element name="forall" type="Logic.type"/>
<xs:element name="implies" type="Logic.type"/>
<xs:complexType name="Logic.type"> <xs:attributeGroup ref="Definition.attrib"/> <xs:attributeGroup ref="Common.attrib"/> </xs:complexType>
<xs:group name="Content-logic.class"> <xs:choice> <xs:element ref="and"/> <xs:element ref="or"/> <xs:element ref="xor"/> <xs:element ref="not"/> <xs:element ref="exists"/> <xs:element ref="forall"/> <xs:element ref="implies"/> </xs:choice> </xs:group>