RE: What is "syntactic identity"? What is "surface syntax"?

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

Would you tell me if my definitions below are correct?  /Roger


1. What is "syntactic identity"?  

Consider this XML snippet:

<Auto-Show>
    <Car>
        <Make>Ford</Make>
        <Model>Mustang<Model>
        <Year>1965</Year>
    </Car>
    <Car>
        <Make>Chevrolet</Make>
        <Model>Camaro<Model>
        <Year>1972</Year>
    </Car>
    <Car>
        <Make>Ford</Make>
        <Model>Mustang<Model>
        <Year>1965</Year>
    </Car>
</Auto-Show>

The Car[1] is syntactically identical to Car[2].

Two elements are syntactically identical if they have the same markup and the markup is in the same order, and the same data and the data is in the same order.

Do you agree?


Although Car[1] and Car[3] have the same "syntactic identity" they are not "identical." 

Two items are identical if they are the exact same thing. Thus, Car[1] is identical to Car[1].

Do you agree?


2. What is "surface syntax"?

Surface syntax is the syntax you see when you open an XML document in a text editor. Contrast that with what an application sees: when an application ingests an XML document the application may represent the XML in a different form.

Surface syntax is also known as concrete syntax.

Do you agree?


Do you agree with the above definitions of:  syntactic identity, identical, surface syntax, concrete syntax?