SPARQL for SKOS integrity constraints

I blogged before on how to test SKOS integrity constraints, constraints which couldn't be expressed with OWL2 as defined by W3C.
I'm aware of two solutions that cover those constraints:

• C&P's Pellet Integrity Constraint Validator which bundles in version 0.4 a skos-constraints.ttl file in the Examples directory
• TopQuadrant's recently announced SPIN implementation to be found at http://topbraid.org/spin/skosspin

Both use SPARQL to check the constraints; the difference being that within the SPIN environment one needs to write the SPARQL queries themselves,
while in the Pellet IC environment OWL axioms (considered under the closed world assumption) are translated to SPARQL in the background.

Anyhow, since I'm still eager to learn more and better SPARQL, I was curious how they compared.
This table summarizes what I found out.

SKOS Constraint	SPIN SPARQL	OWL2IC SPARQL (1)
S13 skos:prefLabel, skos:altLabel and skos:hiddenLabel are pairwise disjoint properties	# Constraint S13a: skos:prefLabel, skos:altLabel and skos:hiddenLabel are pairwise disjoint properties. ASK WHERE { ?this skos:prefLabel ?label . ?this skos:altLabel ?label . } # Constraint S13b: skos:prefLabel, skos:altLabel and skos:hiddenLabel are pairwise disjoint properties. ASK WHERE { ?this skos:prefLabel ?label . ?this skos:hiddenLabel ?label . } # Constraint S13c: skos:prefLabel, skos:altLabel and skos:hiddenLabel are pairwise disjoint properties. ASK WHERE { ?this skos:hiddenLabel ?label . ?this skos:altLabel ?label . }	Validating constraint: disjointProperties prefLabel altLabel hiddenLabel SELECT ?x0 WHERE { ?x0 skos:altLabel ?x1 ; skos:prefLabel ?x1 . } SELECT ?x0 WHERE { ?x0 skos:prefLabel ?x1 ; skos:hiddenLabel ?x1 . } GENERATED FROM OWL axiom [] a owl:AllDisjointProperties ; owl:members (skos:prefLabel skos:altLabel skos:hiddenLabel) .
S14 A resource has no more than one value of skos:prefLabel per language tag	# Constraint S14: a resource has no more than one value of skos:prefLabel per language tag. ASK WHERE { ?this skos:prefLabel ?label1 . ?this skos:prefLabel ?label2 . LET (?label1lang := lang(?label1)) . LET (?label2lang := lang(?label2)) . FILTER ((?label1lang = ?label2lang) && (?label1 != ?label2)) . }	# This condition cannot be encoded as a OWL integrity constraint directly.
S27 skos:related is disjoint with the property skos:broaderTransitive	# Constraint S27: skos:related is disjoint with the property skos:broaderTransitive. ASK WHERE { ?this skos:related ?object1 . ?this skos:broaderTransitive ?object2 . FILTER (?object1 = ?object2) . }	Validating constraint: related disjointPropertyWith broaderTransitive SELECT ?x0 WHERE { ?x1 owl:bottomObjectProperty ?x0 ; skos:related ?x0 . } GENERATED FROM OWL axiom skos:related owl:propertyDisjointWith skos:broaderTransitive .
S46 skos:exactMatch owl:propertyDisjointWith skos:broadMatch , skos:relatedMatch	# Constraint S46: skos:exactMatch is disjoint with each of the properties skos:broadMatch and skos:relatedMatch. ASK WHERE { ?this skos:exactMatch ?exactMatch . OPTIONAL { ?this skos:broadMatch ?broadMatch . } . OPTIONAL { ?this skos:relatedMatch ?relatedMatch . } . FILTER ((?exactMatch = ?broadMatch) || (?exactMatch = ?relatedMatch)) . }	Validating constraint: exactMatch disjointPropertyWith relatedMatch SELECT ?x0 WHERE { ?x1 skos:relatedMatch ?x0 ; skos:exactMatch ?x0 . } SELECT ?x0 WHERE { ?x1 skos:exactMatch ?x0 ; skos:broadMatch ?x0 . } GENERATED FROM OWL axiom skos:exactMatch owl:propertyDisjointWith skos:broadMatch , skos:relatedMatch .

(1) In the case of Pellet ICV I've taken the SPARQL queries as they appeared on stout while using the --verbose argument on the command line.

If you know of other approaches, please let me know.