represents the substitution of the actual parameter instance for the formal parameter and, where required, the substitution of the data type of the actual parameter for the GeneralizedType of the formal parameter and any derivatives. 

represents the EXPRESS "aggregate initializer". 

represents the assignment of a specific value to one Attribute in the group that comprises the PartialEntityType. 

a Reference Expression that returns the value of a given Attribute of a given entity instance 

a subclass of Expression; represents the result of a well-defined mathematical operation or character manipulation on two Expression operands, which are distinguished. 

represents the EXPRESS "complex entity constructor" operator (||). 

a Reference Expression that returns the (current) value of a given Constant. 

Represents the implicit assignment operator that converts a PartialEntityValue to an EntityInstance. 

represents the EnumerationItem value referred to by an EnumItemRef. 

represents an Expression as an interpreted collection of operations. 

an Expression that represents the instance resulting from the invocation of a Function with zero or more Expression operands called "actual parameters". 

a Reference Expression that returns a PartialEntityValue consisting of the values of the Attributes of a given entity instance that constitute a given SingleEntityType. 

a Reference Expression that returns the value of a specified member of a given AggregateValue. 

an abstract subclass of Expression; represents a complex value constructed from other Instances 

a Reference Expression that denotes a specific value of a SimpleType. 

represents the placement of a member value in a particular position in the GenericAggregate value resulting from the aggregate initializer. 

represents an Expression with an unparsed EXPRESS text corpus. 

an abstract subclass of Expression; represents the result of a well-defined mathematical operation or character manipulation. 

a Reference Expression that returns the value of a given actual Parameter. 

represents the EXPRESS "partial entity constructor" named for a 'single entity data type'. 

a subclass of Expression; represents the (aggregate) instance that results from extracting from an aggregate Expression operand the corresponding collection of member instances that satisfy a given select-condition. 

an abstract subclass of Expression; represents a value extracted from another Instance. 

a subclass of Expression; represents the result of a well-defined mathematical operation on a single Expression operand. 

a Reference Expression that returns the (current) value of a given local Variable.