Quantifying conversion efficacy

|e_p| - |v_p| / |v_p| vs. |e_l| - |v_l|

enhance, verbatim, param, layer

DRAFT:

PREFIX rdfs:       <http://www.w3.org/2000/01/rdf-schema#>
PREFIX void:       <http://rdfs.org/ns/void#>
PREFIX conversion: <http://purl.org/twc/vocab/conversion/>

SELECT distinct ?p
WHERE {
  GRAPH <http://logd.tw.rpi.edu/vocab/Dataset> {
    ?versioned a conversion:VersionedDataset .
    OPTIONAL { ?versioned void:subset [ a conversion:LayerDataset; ?p ?o; conversion:num_triples ?triples2 ] }
    OPTIONAL { ?versioned void:subset [ void:subset [ a conversion:Dataset; conversion:num_triples ?triples3 ] ] }
  }
}