Hi,
Reasoning broke for us in 5.1.0.
bash-4.3# stardog query explain -r testSesame "select * where {
> 
>   ?a virksomhet:parent ?b.
> 
> }"
Explaining Query:
select * where {
  ?a virksomhet:parent ?b.
}
The Query Plan:
From all
Distinct [#1]
`─ Projection(?a, ?b) [#1]
   `─ Empty [#1]
bash-4.3# stardog query explain  testSesame "select * where {
  ?a virksomhet:parent ?b.
}"
Explaining Query:
select * where {
  ?a virksomhet:parent ?b.
}
The Query Plan:
From all
Projection(?a, ?b) [#365]
`─ Scan[PSOC](?a, <http://data.einnsyn.no/virksomhetmeta/parent>, ?b) [#365]
Ontology: ontology.ttl · GitHub
Cheers,
Håvard