Replaces every operation whose ranges prove it has no solutions by the empty solution multiset.
The transformation context
The operation to transform
the operation with every provably empty subtree nullified
// Before: SELECT * WHERE { GRAPH ?g { { VALUES ?g { "l" } } } }// After: the GRAPH replaced by FILTER(false), since no graph is named by a literal. Copy
// Before: SELECT * WHERE { GRAPH ?g { { VALUES ?g { "l" } } } }// After: the GRAPH replaced by FILTER(false), since no graph is named by a literal.
Replaces every operation whose ranges prove it has no solutions by the empty solution multiset.