Specifying a transitive depth using the brackets syntax, as described in the SPARQL 1.1 property path language within a SPARQL query causes a syntax error. An example would be:
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
select ?person where { ?x foaf:knows{1,3} ?person . }
In this case, {1,3} would cause a syntax error. Other path depth operators such as ?,+,* work as expected. Would this be an issue that can be fixed or is it a voluntary omission ?