This module operates on RDF graphs represented as
contain blank nodes (bnodes). Bnodes can be considered existential
variables in (sub-)graph, which motivates replacing them by Prolog
- bnode_vars(+RDF, -RDFWithVars, -Vars) is det
- Consistently replace bnodes in RDF with Prolog variable and unify Vars with a list of the variables found. Note that, if we perform matches with such graphs, multiple variables may unify to the same concrete resource. One might consider adding constraints such as dif/2.