ISSUE: List syntax or semantics

TITLE:  List syntax or semantics

DESCRIPTION:
A non-empty owl:List has precisely one owl:first element, and one owl:rest
pointing to a tail.
owl:nil has no owl:first or owl:rest property.

Are these restrictions syntactically or semantically expressed.

Test case:

A:

_:eg <rdf:type> <owl:List>.
_:eg <owl:first> _:a .
_:eg <owl:first> _:b .
_:eg <owl:rest> <owl:nil> .


B:

_:eg <rdf:type> <owl:List>.
_:eg <owl:first> _:a .
_:eg <owl:rest> <owl:nil> .
_:a <owl:equivalentTo> _:b .

(assuming owl:equivalentTo is part of the language)

In the syntactic understanding of owl:List A is a syntax error.
In the semantic understanding A and B entail one another.


RAISED BY: Jeremy Carroll

STATUS: OPEN

TEST CASE: this message

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note I fear that this is the intersection of 5.3-semantic-layering and
2.5-closed-sets.