About: http://webisa.webdatacommons.org/433004280

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Removing both the 1 and 7 from the roof would leave the deadly pattern so either the 1 in B7 must be a solution or the 7 in G7 is a solution.
http://www.w3.org/ns/prov#wasQuotedFrom	sudokuwiki.org