Help with query - Find all requirements without a passed test

[Robert-Adelard]

I'm aware that there's a node group that is supposed to do this, but it isn't quite correct.

The difficulty is that some requirements have both a passing test result and a failing test result.

How do you write a query that only returns requirements without a passing test result?

In particular, for the Turnstile example, HLR-1 and IN_LLR-1 have passing test results as well as failing test results, so they should be excluded from the answer.

It's easy to write the query in SPARQL using MINUS (see #515) but I can't work out how to write it using SPARQL Graph.

Comments / suggestions welcome.